stpm trials 2009 phy q&a (smi ipoh)

8/14/2019 Stpm Trials 2009 Phy Q&A (Smi Ipoh)

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ST. MICHAEl'S INsTlnmoN, IPOHSTPM Trial Examination - 2009Upper Six Sciences

Instruction_ie> ~ d i d a C M :

Pltyslcs 1(960/1)1 hr45 min

There are fifty questions in this tesl For each question. four suggested answers aregiven. You are required to chooee one which is the best answer and marl< on the separateMultiple Choice Answer5_ provided.At1ower . . the questions. Mar1


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- 2-5 A truck of mass 2 600 kg is moving along a horizontal road. When its brakes are applied, heatis produced at a steady rate of 58.5 kW for 5.0 5 before the truck stops. Estimate the speed of thetruck just before the application of the brakes.

A 10.0 m 5.1 C 15 .0 m 5.1 o 22.5 m 5"6 A steel ball of mass 0.005 kg fa lls vertically through a liquid at terminal speed 0.1 m 5" , Theenergy dissipated per second in the liquid by the ball 's motion, in mJ, is

A 0.025 B 5.0 C 10 o SO7 The radius of curvature of the North-South Highway at a certain place is 200 m. At what anglemust its surface be banked so that a car moving with a speed of 108 km h-I will not experience anylateral strain on the wheel?

A zero B 24.6 ' C 61 .6 ' o 65.4 '8 To what quantity in linear motion is the moment of inertia of a rotating bod y analogous?

A force B momentum C acceleration o ma ss

9 The diagram shows a metre rule which is placed on a smooth horizontal table.smooth table metre rule

t t ; ! I i : ; ! p 9 " * ' i ,

impulsive force

When a horizontal i m p u l s i v ~ force is applied to one end of the meter rule in a d irectionperpendicular to its axis, the metre rule will experienceA translation only.B rotation only.C rotation and translation.o vibration , rotation and translation.

10 A body of mass m s placed on a rough surface that is inclined at an angle of e to thehorizontal.

If the body remained stationary, the coefficient of static friction J.I is givenA ~ = m g C ).1= mgkos 9B ~ = m g \ a n o f1= tane

11 The escape velocity of a carbon dioxide molecule On the Earth's surface is 1.1 x 10" m 5 .1, Whatwill be its escape velocity at an altitude of O.4R , where R is the Earth's radius?A 0.9 X 10" m 5.1B 1.1 x 10"ms1 C 1.3 x 10" m 5"o 1.5 x 10" m 5"

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-3 -12 The graph on the right shows the variation ofthe gravitational potential energy U of a spacecraftwith its distance r from the Earth's centre, Theradius of the earth is R

uR "O ~ - - - - - - - + ,

- U, - ---f- -- - - -.:;--'--If the spacecraft is orbiting the Earth in anorbit of radius r , the total energy of the spacecraftis - U,

c 2U ,

,,,,,,

13 When the amplitude of a simple harmonic motion changes, which of the following quantitiesdoes not change?A period C acceleration8 velocity D restoring force

14 A frictionless trolley of mass 1.0 kg is tied to two f i x ~ points, X and Y, using two stretcheds P r i n g s

! m e Y I ~ Y c) 0=- xThe trolley is displaced a small distance (0.050 m) towards Y by a force 5.0 N and then released .The subsequence motion is represented by the equation a = oo zx, where x is the displacement of thetrolley from its equilibrium position. What is the value of 002 ?

A 0.25 radz s ' zB 1.0 radz s""2 C 100 radz s 'o 400 radz S ' 215 Diagrams (a) and (b) show the displacement--distance and displacementtime graphs of atransverse wave.displacementlmm displacementfmm

of\J\J distance/em(a)

of\PJa(b)

.. tlme/ms

The velocity of the wave isA 0.004 m s, B 0.4 m s' \ o 4ms' \

16 Which of the following statements is no t true about stationary waves?A Particles between consecutive nodes vibrates in phase.B Particles between consecutive nodes vibrates with the same velocity.C Particles between consecutive nodes vibrates with different amplitude.D Particles between consecutive nodes vibrates with the same frequency.

17 A spectator is standing by the side of a racing track. When a Formula1 racing car passes him,he observed that the pitch of the sound produced by the car decreases. This is due toA Doppler effect. C damping.B resonance. o reflection.

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- 4-18 A point source produces a sound at the rate of 120 W. What is the intensity level of the soundat a distance of 2.0 m from the source? [threshold of hearing , 10 = 10.12 W m'2j

A 30dB B 124 dB C 130 dB D 141 dB

19 The diagram below shows the extension (x) of a wire varies when it is stretched by a force (F).F

o LL-_--.l'-__ XThe shaded region represents theA strain in the wire.S stress on the wire.C strain energy stored in the wire.D strain energy per unit volume stored in the wire.

20 The graph shows how the potentialenergy U between two atoms in a diatomk:moJecule changes with the distance ofseparation r between them.At a certain temperature T, each atomv i b r a t e ~ between two positions which arerepresented by the points P and Q .The maximum thermal energy of themolecule at temperature T is

A E. B E, . E. C E, + Eo

u

oE,Ii. ..

,Q

D

21 The r.m.s. speed of the molecules in an ideal gas of volume V and pressure p is Co . The gas isheated until its volume becomes t V and its pressure becomes 6p. lNhat is the new r.m.s. speed ofthe molecules?

A 2e. B 3e. C 4e. D Be.22 The graph below represents the distribution of molecular speed in a gas at temperature T .number ofmolecules,

n(v)

z speed, vThe quantity z is theA modal speed (most probable speed).B root mean square speed.C mean square speed.o mean speed.

23 Which of the following equations is not applicable to an ideal gas undergoing adiabaticchange?A dO=OB pV=nRTC pV = onstanto TV'" 1 = onstant

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- 5-24 Two c:onduc:ling biocks are maintained at 8 temperature di1ference of 20 K. and are connectedthrough tW


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- 6 -30 Six identical resistors, each of value 5 f l , are connected to a 2 V cell whose internalresistance can be ignored.~ - - - - - - - - - - - - - - - - - - - - - . X

2V ry L -_ _ _ _ _ _ _ _------_ _ _ _ _ _

The potential difference across X and Y isA 3.v) B Jlv9 c v)

31 The diagram shows a 40 em straight conductorcarrying a current 0[20 A in a 2.0 T field.The magnetic field acts in the horizontal plane atan angle of 8 with the direction of the current.If the weight ofthe conductor is 8.0 N and themagnetic force is just enough to balance the weight

of the conductor, what is the angle (f!

32 The figure shows the trajectoriesof two charged particles P and Qshot perpendicularly into a region ofuniform magnetic field with thesame velocity.If the radii of the trajectories are

the same, identify P and Q.

p QA a-particle electronB electron a-particleC electron positron0 positron electron

33 The figure shows the side viewof a circularcoil ofN turns and areaA in a magnetic field B.

Ifthe normal to the plane of the coil makesan angle q with the magnetic field, the totalmagnetic flux through the coil is

o

2IIA

p - -.-o --+_ -

Qrcularcol

,_ - - - . - : " ~ L - - - B

A NBA casu B NBA sinu C BAcosu o BA sinn

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-7 -34

1:tW:crrrrr:::Imcrg:ucr& Soft " '"CoilR

In the circuit above, switch S is closed and the current in the coil is increased gradually byadjusting the rheostat. When the current is at its maximum, switch S is opened. The deftectionshown on the galvanometer is largestA at the instant switch S is closed .8 while the current in the coil is increasing.C when the current is at its maximum.o at the instant switch S is opened .

35 In a circuit, an alternating CUlTent of r.m.s. value 1.00 A flows through a resistor. In anotherc ircuit, a steady current ofmagnitude I flows through an identical resistor. If the two resistorsdissipate heat at the same rate, the value of I is

A 0.71 A B 1.00 A C 1.41A o 2.00 A36 A sinusoidal voltage of r.m.s. value 0.60 V is connected to a 30 mH inductor. If the peak currentflowing through the inductor is 45 mA, what is the frequency of the a.c.?

A 18 Hz B 100 Hz

37 The figure shows the symbol o f anoperational amplifie r.Which terminal and label do notcorrespond?

Terminal LabelA P Inverting inputB Q Non-inverti ng inputC R Feedback output0 S Sig nal output

C 110 Hz

~ - - I o ~ - - I '

38 The figure shows an operational amplifier circuit.lOll,.,

, .'", K:r-t:-r:. _10VI - ' -

o 630 HzR

IV.

Which graph represents the variation of he output voltage Va with the input voltage Vi?

s

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A

C

- >0

~ 5 , ,,

."0 2.61 V;IV

_10

V,.IV

."

-10

- 8-B

D

-" ,

."0 " Vi/V,,,-10

V.N

.10

, V;IV39 In photoelectri c emission, the energy of the photon is used

A as the kinetic energy of the electron on ly.e to release the electron from the lattice only.C by the electron to produce a new electron called photoelectrono to release the electron from the lattice and as the kinetic energy of the electron.40 A proton and an electron have the same value of the de Broglie wavelength. If the K E. of theproton and the electron-are. respectively, Kp and 1 K,

41 The figure shows some of the energy lev elsof an atom.

The maximum number of spectral linesproduced by the transition ofelectrons fromthese four energy leve ls is

A 3 B 4

C Kp=K, o IK = -P K,---- ---- - - .----------,- ----- - - - - ,-----------,

C 5 o 6

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42 The graph shows the X-rayspectra I and II produced by an X-raytube when it is operated at twodifferent voltages.

Which statement explains why theminimum wavelength of spectrum II islon ger than that of spectrum I?

- 9-

A A higher voltage is used to produce spectrum II.B A lower voltage is used to produce spectrum II.

':"" I

Wavelength

C An element of smaller atomic number is used as the ta rget material to producespectrum II .o An element of bi gge r atomic number is used as the target material to produce

spectrum II.

43 The penetration power o f of X-rays produced from an X-ray lube can be increased byA increas ing the length of the X-ray tube .B increasing the operating voltage of the X-ray tube .C increasing the current flowing through the cathode .o changing the target metal to an element of higher atomic number.

44 The nucleus of iron Fe is more stable than the nucleus o f bi smuth z:; Oi . Which of thefoll owing is true of the more stable nucleus?

A Smaller mas s per nucleonB Lower ratio of proton to neutronC Lower binding energy per nucleono Higher binding energy per nucleon

4S When a s low neutron is captured by a stationary Cd nucleus, a I::Cd nucleus is formed anda 'Y4ray photon is emitted. What is the wavelength of the y -ray?[Mass of = 1.0087 u, mass of ':: Cd "" J 12.9044 U, mass of I:;Cd "" 113 .9034 uJ

A 2.0SxlO-23 mB 6.63 X10- 16 m

C 1.37 X \0 -1) mo 1.45 xlO-12 m46 A radioactive sample consists of a nucl)de which emits a-particles at the rate as shown in thegraph below. _01"""""

Determine the decay constant of the nuclide.A 5.5)( 10-3 S1 B 9.2x 10 -3 5-' C 75s o 125 s

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- 10 -47 A radioactive element X decays to a radioactive element Y which then decays to element Z. Ifthe sample initially contains X only, which of the following factors influences the ratio or thenumber ory nuclei to the number of X nuclei after a certain time?

48

A Half life of element YB Halflife of element Z

"x ->m 'ioC Initial number of X nucle io Surrounding pressure

+ ',YThe equation above represents a nuclear reaction. What do the symbols m, nand Y represent?

!I! !LA 4 2B 2 4C 2 40 - 1 0

49 The antiparticle of the electron is theA quark B me son

50 The strong force is responsible forA bela decay.B alpha decay.

Xnucleonneutronprotonhelium nuclide

C neutrino D positron

C binding the nucleons together.o holding the electrons in the atom.

960 P HYS ICSValues ofconstantsSpeed of light in free space cPermeability of free space 1'0Permittivity of free space ..Magnitude of electronic cha rge ePlanck constant hUnified atomic mass constant uRest mass of electron m.Rest mass of proton m,Molar gas constant RAvogadro constant L. NABoltzmann constant kGravitational constant GAcceleration of free fall g

Prepared by : Lee Ping Kew,August, 2009 Checked by :PRAKAs

LPK@C:IPIIYSICSFORM6lEXAMl09STPMT,ia[ PtJfMrf .doc:

============

0 0 0 ' m s ~ 41tx10 , THm , !8.85 x 10 . 12 F m 1(1/(36n)) x 10" F m"1.60 x 10 , n C6.63 x 10 , 3-4 J s1.66 x 10 2T kg9.11 x 10 , 31 kg1.67 x 10'27 kg8.31 J K . , mar6.02 x 10 23 mol -'1.3Bx10 23 JK-t6.67 x 10 . 11 N m 2 kg 29.B1ms -2

Endorsed by/?a-w'1:..U .c;u", Kmrtm $a ifUSML St.Midwd

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ST. MICHAEL'S INSTITUTION, IPOHSTPM Trial Examination - 2009Upper Six SciencesPhysics 2(960/2)2 hr 30 min

Full Name: _ __ _ ________ Class No.: Class: Upper Six Science__(as in the Class Register)Instructions to candidates:

Answer all the questions in Seclion A in the spaces provided. Al l working must be shown. Forcalculations, relevanl values o fconstants in the Data Booklet must be used. For numerical answers,units must be quoted wherever they are appropriate.

Answer any (our questions from Section B. For this section, write your answers on the answersheets (test pad) provided. Begin each answer on afresh sheet o/paper, and arrange your answers innumerical order. Tie your answer sheets to this question booklet (from page I to page 6 only) ljnecessary, use the values ofconstants provided on page 10 in this question booklet.

This question booklet consists of 10 printed pages

Section AAnswer all the questions in this section.

1 (a) Define a vector quantity.... ........ ............... .. . . ...... .. ............... ..... ..... ........... ........ .... .............................. ..........

(b) A r!gid wire frame is in the form of a cube. A force of20 N is applied along a diagonal from the origin 0 to a pointA which is diagonally opposite to O. Refer to the Figure onthe right.

Three forces of equal magnitude, each parallel to a side ofthe cube, are then applied at point O.Determine the magnitude and direction of these three

forces so that they will balance the 20 N force.

96012

z

,,,,

f - - -

y20N

O V " ' ' ' - ~ - - T - - - - ~ x

,-------y,,,,

[1 J

[4J

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- 2-2 The archerfish hunts by dislodging an unsuspecting insect from its resting place with a streamof water expelled from the fish's mouth. Suppose the archerfish squirts water with an initial speed of2.5 m 5"1 at a beetle on a leaf4.0 em above.the water's surface, as shown below.

(a) If the fish aim in such a way that the stream ofwater is movirlg horizontally when it hits thebeetle. what is the launch angle, 9?

(b) How much time does the beetle have to react?

(e) What is the horizontal distance, d, between the fish a n ~ the beetle when the water is launched?

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[2 ]

[2]

( I]

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- 3 -3 Figure (a) shows the bone and muscle structure ofa person's arm holding a 5.0 kg mass inequilibrium. The forearm is horizon tal and is at right ang les to the upper arm. Figure (b) shows theequivalent mechanical system. fM is the force exerted by the biceps musc le and FJ is he force at thee lbow joint.

E

om

20N

35cmFigure (a)

pE r + - ~ r - - - - - - - -

5.0om _N

om35 em

Figure (b)(a) (i) Suggest a reason why a 20 N fo rce has been inc luded in this system.

5.0 kg

(i i) State the condi tion(s) that must be met by the forces when the arm is in equilibrium.

(b) Calculate the magnitude orlhe force FM .

(e) In many a thletes, the distance between the e lbow jo int (E) and the muscle attachment (P) isgreater than 5.0 em. Ex plain why this is an advantage in lifting and throwing events......................................................................................................... ................. .......... ................................... ............................................................. ........................................................ ...... ..... ....................

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(1)

[2)

[ I)

(1)

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- 4-4 (a) State the first law of thermodynamics.

(b) Explain the following observations:(i) when gas from an aerosol can is suddenly released, the container becomes cooler.

(ii) while pumping up a bicycle tyre, the pump barrel becomes warmer.

5 An ideal solenoid consists of 1000 turns of wire per em wound around an air-filled cylindricalstructure. The solenoid is of2 .0 em long and cross -sectional area 1.8 cm2, A current of2 .0 A passesthrough the wire.(a) Calculate the magnetic flux in the centre of the solenoid.

(b) Calculate the self-inductance of the solenoid.

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/1)

(2)

[2)

II I

[2J

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- 5 -6 A sinusoidal a .c. supply is applied to the circuit as shown below

. - - - - - , D ~ - - - - - ,

a.c ...., R

L- - - - - - - - - - - - - - J a(a) (i) Write down the equation representing the potential difference between A and B. [I [

(ii) On Graph I below, sketch the variation with time of th e potential difference between Aand B for two cyc les. [I]

(b) A diode is then connected to the circuit at point D. On Graph II below, sketch the variation [ 11with time or the potential difference between A and B for two cycles.

(e) (i) Describe how you would modify the circuit in o rder to smooth en th e p.d. across AB. [11

(ii) After the modification , sketch the variation with time of the potential difference between Aand B for two cyc les on Graph III below.v v v

01-----+ o oGraph I Graph II Graph III

7 (a) What is a photon?

(b) A p.d. (V) is applied across a photoce ll as shown in Figure (a). The photocell is thenilluminated with monochromatic light of wavelength 365 nm. The current in th e circuit is measu redfor various values of V. The results are shown in Figure (b).

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vFigure (al

,V,rl .,..d.c. ,uppty

(i) Deduce the value of the stopping potential.

-, , ' wvFigure (bl

[IJ

[1J

(1 J

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6

(ii) Calculate the maximum kinetic energy of the photoelectrons emitted_

(iii) Determine the work function of the cathode materiaL

8 The initial number of atoms in a 4.0 g radioactive element is 8.0 x 10 21 The half-life of theelement is 5 hours.(a) Calculate the number of atoms which decay in 12 hours.

(b) Determine the mass of the radioactive element ~ f t after 24 hours.

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[1 )

[2)

[4)

[II

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- 7-Section B

Answer any four questions in this secl ion

9 (a) Describe briefly the characteristics of a projectile motion.(b) A ball-bearing of mass 50 g rolls of f the edge of a horizontal platform at a height 2.4 m and

strikes the floor at a horizontal distance of3.2 m from the edge of the table.

[2]

(i) Ca lculate the time taken by the ball-bearing to reach the floor. [2](ii) Determine the speed of the ball-bearing just before it falls. [2](iii) Calculate the magnitude and direction of the velocity of the ball-bearing just befort: it hilsfu_(iv) Dctennine the average power of the ball-bearing. 14]

10 (a) (i) Stale Newton 's law of universal gravitation. [2](ii ) Define gravitational fie ld strength. [I]

(iii) Use your answer to part (i ) and (ii) to show that the magnitude of lhe gravitational field [2]strength at the earth's surface (Eo) is given by the exp ression :It: GM where M is the mass of R'the ea rth, R is the radius o f the earth and G is the gravitational constant.

(b) A communication sa tellite is in an orbit such that its period of revo lution around the earth is 24hours .

(i) Explain the significance of this period.(ii) What is the term given to this particular orbit?(iii) Show that the radius of the orbit, Ro, is given by R VGMT 24n '

of the orbit, and G and M have the same meaning as in (a)(iii).where T is the period

(c) Estimate the minimum kinetic energy which must be given to a sa tellite of mass 2500 kg at

[2][I][ 2]

the earth's surface for it to reach a point which is at a distance Ro from the centre of the eanh. State [5]two assumptions made in your ca lculations.

[M 6.0 x 10" kg, R 6.4 x \0 ' m]

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- 8 -11 (a) (i ) State two assumptions of an ideal gas. (21(ii) State two physical conditions under which a real gas behaves as an ideal gas. [2](iii) A 0.45 m ) tank contains 8.0 kg of butane gas. Assuming that the gas behaves as an idealgas, calculate irs pressure at 27c ' (3][Molecular mass of butane is 58 g mor l 1

(iv) Butane gas normally behaves as a real gas. The aelUal pressure of the butane gas is higherthan the calculated value in (a)(iii). Give a reason.

(b) (i) What is meant by the degrees of freedom of a gas molecule?(ii) Write an expression relating the total kinetic energy E of a gas molecule to the number of

degrees offreedomf Explain any other symbols used.(iii) The escape ve locity ofMars is 5.0 x 10) m 5. 1 If the temperature of Mars is 300 K, determine

whether oxygen gas can exist on the planet.[Molecular mass of oxygen is 32 g mol'l 1

12 (a) Two thin conducting plates have an area of 0.50 m2 each. They are placed para llel to each otherand 20 mm apart. One plate is maintained at +75 V while th e other at - 75 V by a d.c. supply.(i ) Determine th e amount of charge stored on each plate.

(ii) Calculate the ene rgy per unit volume stored in the electric fi eld between the plates.(b) The figure shows a simple circuit of the photographic flash used in a camera.

The capacitance of the capacitor is 40 .0 ....F, and the resistance of the resistor is 45.0 k!l.

[ I)[I)[2)[4)

[3][3]

(i) Ex plain how the capacitor functions in this application. [41(ii) Ca lculate the time required to charge the capacitor to 63% so that a good flash can beobtained. [4]

(iii) Suggest a way to reduce the charging time of the capacitor. [I ]

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- 9-IJ Figure (a) shows how two op-amp are connected together in series. Both are suppl ied with 9.0 V. Figure (b) shows how the voltage gain of a non-inverting amplifier de pends on frequency.

input0----1+

Figure (a)

1 kU

+

OV

output22kUPUcU

OV

Voltage gain200'

2k20020

23 30 300 31t 30 k lOOk 3Mfrequency ' Hz

Figure (b)(a) (i ) Name the type o f feedback c ircu it used.(ii ) Explain the meaning of this type offeedback.

(iii) State two advantages of this type o f feedback.(b) (i) Calculate the voltage ga in of each individual amplifie r.(ii ) Deduce the voltage gain of the whole system.(e) A steady vo ltage of - 3.0 mV is app lied to Ihe input of the system.

(i ) Determine the voltage at the output.(ii) Calculate the e lec tric potential at po int P.

(d) A s in uso idal a.c. of peak voltage 30 mY is then applied to the input.On the same axes, sketch the graph of(i) the input voltage against time.(ii) the output vo ltage aga inst time.In you r graph . label each line carefully and labe l all the important va lues on the axes.

(e) Using the graph in Figu re (b), estimate the bandwidth of the whole system.

14 (a) Give the meaning of eacn of the following terms.(i) nucleon number(ii) proton number

(iii) binding energy(b) The structure of the nucle us was investigated by the experiment shown in the Figure below.

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protonsintense radiation

beryllium solid containinghydrogen atoms

[I][I j[2][ I][ I ]

[ I][21

[4 1

[21

[II[I j[2]

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- 10 -Alpha particles were fired at a piece of beryllium and an intense radiation was found to be

emitted from the beryllium. When this radiation entered a hydrogen-rich solid, protons wereknocked forward from the solid. The initial reaction in the beryllium is

tHe + tBe -> dn + IgC(i ) In the above equation, which symbol is used to represent the alpha particles?(ii) What information does the symbol give about the alpha particles?(iii) Suggest, with a reason, which particle is responsible for knocking a proton oul of thesolid containing hydrogen atoms.(iv) The intense radiation was originally thought to be y-rays. Why does the existence ofthe knocked-forward protons make this impossible?

(c) The masses of the particles in part (b) arc as follows.i He + :Be ---+ +4.00260 u 9.01212 u 1.00867 u 12.0000 u

[1 J[1)[2J[2J

(i) Calculate the mass defect. in kilogram, in the reaction. [2J(ii) Hence. find the energy equivalence of this mass defect. Express your answer in MeV. [31

960 PHYSICSValues of constants

Speed of Itght in free space cPermeability of free space Po =Permittivity of free space Co =

=Magnitude of electronic charge e =Planck constant h =Unified atomic mass constant u =Rest mass of electron m, =Rest mass of proton m, =Molar gas constant R =Avogadro constant L. NA =Boltzmann constant k =Gravitational constant G =Acceleration of free fall g =

Prepared by: Lee Ping Kew,August, 2009 Checked by:

3.00 x 10 ms4nx10 7 Hm- 18.85x 10 12 F m 1(1/(36n)) x 10. 9 F m- 11.60 x 10 - 19 C6.63.x 10 -3 4 J s1.66x 10 2 7 kg9.11 x 10- 31 kg1.67 x 10 . 21 kg8.31 J K -1 mol'6.02 x 10 23 mold1.38x10 23 JK 16.67 x 10 1 1 N m 2 kg 29.81 m S-2

Endorsed by :

. . ._ '-LPK@C:PHYSfCSFORM6lEXAMI09 STPMT i8JPspor2.doc

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S.M.K. ST. MICHAEL IPOH STPM TRIALS 2009PHYSICS PAPER 1 (ANSWERS)

1 C 26 C2 D 27 C3 C 28 A4 B 29 B5 C 30 A6 B 31 D7 B 32 D8 D 33 A9 C 34 D

10 D 35 B11 A 36 B12 A 37 C13 A 38 A14 C 39 D15 D 40 B16 B 41 D17 A 42 B

18 B 43 B19 C 44 D20 B 45 C21 B 46 B22 A 47 A23 C 48 C24 D 49 D25 A 50 C

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1 (a)(b)

2 a

b

c

ST. MICHAEL'S INSTITUTION , IPOHSTPM Trial Examination - 2009Upper Six SciencesPhysics 2

(960/2)2 hr 30min(Marl


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3 a(l) This is to lake into account of the weight of the forearm. 1(ii) 1. The resultant force in any direction is zero. 12. The ~ u l t a n t moment about any pOint is zero. 1b Taking moment about E. .eO) { " ) {")F" - " 2 - + (5.0X9. 81 -100 100 100

FM "" 403N 1

c The fOfce (F loC) exerted by the athletes witl have a greater moment about the elbow E. 1TOTAL 5

4 (a) The heat supplied to a system equals to the sum of the increase in its internal energy and 1the external work done ID: the system.(b) (i) Work is done the gas us ing part of il s internal energy. 1

Since the gas expands adiabatically, heat does not flow inlo the sys tem causing its 1internal energy to decrease.(ii) The work done on the gas is changed into internal energy. 1

Since the gas is compressed adiabatically, heat does not flow ou l of the system 1causing its internal energy to increase.TOTAL 5

5 (a) Magnetic flux density, B "" 1J.,n1= (4rr x 10.7)(1000 x 102)(2 .0) converl 1000 em" 10 m"= 0.2513 T 1Magnetic flux, = BA= (0.2513(1 .8 x 10 -4)= 4.523 x 10 -5= .52 x 10-liWb 2ORMagneliejlux, f/> ... BA

- (P",I)A... Iq ')(I000x Ui) (2.0)(1.8x I fr )- x ur Wb

(b) Magnetic flux linkage, ' = N= ( n ~ 4>= (2000 x 2)(4.523 x '0") . NB: n is in em" , lis in em .. o.t 1:c 0.09046 'Ml

Also ' = I IL = '/1= 0.0904612.0 1= 4.52 X 10 .2 HTOTAL 5

- 2 -

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.- - ----6 (a) (i) V' " Vo Sin wi 1(e) Connec t a capacitor parallel to R. 1

.V V V 1[(\ f'I oV\ f\ , , ' , 1- . 0 , , 0 . . . ,TVT T 2T T 2T 1(a)(ii) ~ a P h I (b) Graph Il (c)(ii) Graph I II TOTAL 5

7 (al .... a packet (quantity) of electromagnetic energy. 1. . .-(b)(;) 1.0 V 1(ii) Em&>! - eV , :; (1.S0 X 10" ")(1.0) 1.60 X 10' J 11 1.0 eV 1(iii) E ..... - hf-W oWo=hf-E", .

::: he_ EA. max= (6.63xIO- 34X3.0xI08) - (1.6OxlO - 19 )365)(10-9= 3. 85 X 10 .1 J II 2.41 eV .2

TOTAl T

8 (a) Numbe r of halt lites, n '" 1215 2.4 1Number of radioactive atoms left, N =No( Xi f= B.OX 1021 ~ Y : i )2 .4= 1.5 16x10 1 1Number of radioactive atoms decayed ::: No - N= .0 X 1021 - 1.516 X 1021. = 6.484 X 1021= .48 X 1021 1

(bl Number of radioactive atoms left after 24 days, N No( Xi )= 8.0 X 1021 ~ Y . i )2


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Section B9 (a) 1. Horizontal component: Motion under constant speed .Vertical component: Motion under uniform acceleration (a ;: g, acceleration of free-fall). 12. The trajectory (path of projectile) is a parabola . 1

(b) (i) Consider vertica1 motion:Use: s:::ut+ y. at2 , , ~ . 2.4 = (0) + Y.i (9.B1)e


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,.

.

a

b

(c)

(i) Newton's law --- th e gravitational force between two bodies is directly proportional 10the product of their masses and inverse ly proportional to the square afthe distancebetween them. 2

(o r, in equQ{ionjormprovided meaning of al/ the symbols are given).-(ii) Gravitational field strength --- gravitational force acting on a unit mass 1

(iii) Consider a body of ma ss m on the Earth'ssurlace.Gravitational force, F = G AI; ;? mRFBy definition, E. ,= -m

( G ~ ~ l M= 2mGM (diagram optional)- fi2

(i) 1. li s period of revolution equals to the period of rotation of the Earth. 12. Its position relative to a fixed point on Earth does not change. 1(ii) Geosynchronous /I geostationary /I parking orbit [-;-.1(iii) 'v\Ihile in orbit,centripetal force = gravitational force, Mm.. maJ Ro '" G - - 1R.

.. m(2JtyR =G MmT ,R.

.. Ro =VGMT24,' 1I--

radius of orbit, Ro =VGMT24, '= 3 (6.67.xlO IIX6.0xl024X24x60x60)2, 4,'= 4.23 X 107 m 1

6,K=Uo - U, , where Uo = P.E. at distance Ro, U1=P.E. at Earth's surface.= _GMm_(_G Mm )R. R= GMm( - ' ~ _ 1R.= (6.67 x I O ~ I I X 6 x 1024X2500{ I 6 - 1 7) 16.4 x 10 4.23 x 10= .33 X 10 11 J 1

Assumptions: 1. No air resistance 12. Speed of the satellite at level Ro s zero. 1TOTAL 15-, 5 .

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11 (a) (i) Assumptions1. The internal energy of the ideal ga s consists only of the total kinetic energy of thegas molecules.2. There is no force between the gas molecules except during collisions. 2.3. Collisions between the gas molecules are perfectly elastic.4. The volume of the gas molecules is negligib le compared to volume of the gas.(any two)

(ii) 1. Allow pressure II when the pressure approaches zero.22. At high tem perature.

(iii) For an ideal gas, pV =(; )RT 1Thus, pressure, mRT~ MV

_ (8.0 X8.31 X27 + 273 ) m, M must in kg (SI unit) 1- " 8 x l ? X O . 4 1.64 x 10 Pa

(iv) At this high pressure of 7 .64 x 10 Pa , butane gas deviates from the behaviour of theideal gas /I The volume of the gas molecules is nol negligible. 1(b) (;) Independent modes of motion the gas molecule IIIndeQendenl modes of acqutring kinetic energy by the gas molecule. 1

(ii) , .L kT2 1where k is Boltzmann's constant and T is the therm odynamic temperature of the gas. 1

(iii) Translational K.E. :c f mv 2 = t kT.. v : J 3 :r

== J 3Rr using: m = (MIN.J and kNA RAt3(8.3 1X300 1. = V. J2 r iO - I

'" 483 m s'\ 1

This velocity is less than the escape velocity of Mars (i.e. 5.0 x 103 m S I ) II 1oxygen molecules can not escape from the gravitational pull of MarsThus. oxygen can exist on Mars. 1

TOTAL 15

6

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12 (a) (;) Q CV;/)v( 8 085XW")(0050) )[75 _(- 75)J20x IO-)

= 3.3 186 x 10-e=3.32x 10"C

energy stored in the capacitor(ii) energy per unit volume = .volume _of _ the _electric _ field=tQVAd 0 0

+


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13 (al (II Negative feedback 1(ii) A fraction of the output is fed (applied) to the inverting input. 1(iii) 1, The voltage gain is independent of the op-amp characteristics., 2. The amplification is constant over a wider frequency range.3 . Distortion of the output is reduced. 2(Any two)

(bl (II R fA= + 1R ,= 22k +1Ik= 23

(ii) (231 = 529 1(cl (II

Vi= AVo:: (S29)(- 3.0 x 10 ..:1 )

1= -1.S89V

(ii) Vp = Ik x(- 1.589)Ik + 22k 1= - 0.0691 V 1

(dl ='1;;':+ , ,1- j- _ /-1-\ ' . l L . / i ' I I I, " , ,. !. ' , , . ii- - - - 2, - r ' ,- - I" -- 1,m" ,iJ, , 17" , /, , , ," , , , , ,, , , , , ,- .3 ImV - ":: .... I- - '- - "',' '- -, 2

1 ~ f I t 1 1 -l-- v - I \- , - ' - , - ,-- 1-- [ -,- , \ , , \ I, - , ~ - - - - - - , - . . - \11 I \1-1 -"l'V, ' T ' I Ir =1==l= - -r---r -+L ,J I , I __ _ , INB : If there's no saturation. peak voltage of output = A (VJ peak= 529x30mV

= 15.9 V

(el 3 Hz to 9.5 x 10 Hz 2TOTAL 15

,8 ,

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I . (a) (i) Tolal number of protons and neutrons in a nucleus .1 1(ii) Number of protons in a nucleus. 1 1

(iii) The amount of energy required to completely separate all the nucleons in the 2 2nucleus_ ,,

(b) (;)42He 1 1

(ii) an alp ha particles consist of 2 protons and 2 neutrons. 1 1(iii) the neutrons 1 2reason: the C-12 nucleus is too large to penetrate the solid . 1(iv) The emitted protons have momentum in the forward direction. 1

Thus, it requires thai the incident particles have at least the same momentum. 2h 1V-rays will have much smaller momentum ( ie, P = A. )

(e) (;) t.m = (4 .00260u + 9.0 1212u) - (1 .00867u + 12.00000u)= 0.00605u 1= ( 0 0 0 6 0 5 ~ 1 x 10 -21 ) kg 2= 1.DOx 10 kg 1(ii) E me= 1.00 x 10 -.2')(3 .00 X 10 11) 2= 9 .00 x 10 _13 J 1

9.00 x 10 _ Il eV(1.60 x \0 - ' ., ) J9.00 x 10- 13 1= ( 1.60 x 10 19 )(106) MeV

= 5.63 MeV 1TOT AL 15

9

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stpm trials 2009 phy q&a (smi ipoh)

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