phy qp 4 prescreening

8/13/2019 Phy QP 4 Prescreening

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Physics Question Paper for Prescreening

Section A

1) Below graph represents the position as a function of time. During these three differentregions I, II & III what was the highest speed?

2) What is the magnitude of the impulse by the bat to the ball of mass 0.15 kg travellinghorizontal with speed of +20 m/s and reverses its direction with same speed after hit?

What is the average force exerted when the ball in contact with the bat for 1.3 ms.

3) Two particles of masses 7 kg and 3 kg are connected by a taut, light, inelastic stringwhich passes over a smooth light pulley. The system is at rest. Find the common

acceleration of the particle and tension in the string?

4) The electric field in a certain region is in the direction. Its magnitude is. What are thedirection and magnitude of the electric force on a charge placed in this region if (a) and

(b) ?

5) A proton is accelerated from rest by a potential difference of 400 V. The proton enters auniform magnetic field and follows a circular path of radius 20 cm. Determine the

magnitude of the magnetic field?

Section B

6) Model rocket engine is sized by thrust duration and total impulse. A size C5 model rocketengine has an average thrust of F = 5.26 N, a fuel of mass m = 12.7 g, and an initial mass

of m0 = 25.5 g. The duration of its burn is t = 1.90 s. What is the average exhaust speed

of the engine? If this engine is placed in a rocket body of mass M 42.5 g, and if the


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rocket is fired in outer space, what is the final velocity of the rocket? Assume burning is

constant.

7) Find the pressure difference needed to make water flow through a tube of length 25 cmwith diameter of 1.2 mm at 0.3 mL/s? Viscosity of water is 1.00 mPa.s.

8) What will the percentage increase in the rms velocity of the molecule when thetemperature of a gas is raised from 27 to 90 degrees?

9) Find the tension in each rope when a 700-N person is 0.500 m from the left end on auniform plank of length 2.00 m and mass 30.0 kg is supported by three ropes?

10)An infinitely long rod of negligible radius has a uniform charge density . Calculate theelectric field at a distance from the wire?

Section C

11)Find the common acceleration and the tension in the string connecting the blocks ofmasses 2 kg and 3 kg, resting on a rough horizontal table. The 3 kg mass is connected by

a second light inextensible string passing over a smooth light pulley at the edge of the

table to a particle of mass 5 kg. The coefficient of friction between the 2 kg mass and the

table is 0.125 and between the 3 kg mass and the table is 0.25.

12)How much work is done the motor of a centrifuge exerts a constant torque of 0.8 Nm.Moment of inertial is I=0.2 kgm^2. Find the angular velocity in rpm when it rotated

through four revolutions?

13)How much energy would be required to accelerate a particle of mass m from rest to aspeed of (a) 0.5c, (b) 0.9 c, and (c) 0.99 c? Express your answers as multiples of the rest

energy.

14)Two spaceships pass each other traveling in opposite direction. A passenger on ship A,which she knows to be 100 m long, note that ship B is moving with a speed of 0.92c

relative to A and that the length of B is 36 m. What are the lengths of the two spaceships

measured by a passenger in B.

15)A small ball of mass 2x10-3kg having a charge of 1uC is suspended by a string of length0.8 m. Another identical ball having the same charge is kept at a point of suspension.


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Determine the minimum horizontal velocity which should be imparted to the lower ball

so that it can make one complete revolution?

phy qp 4 prescreening

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