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TUTORIAL 9 ALPH10)FORCENEWTONS L WS OF MOTION

1. State the definition fora. Newtons First Lawb. Newtons Second Lawc. Newtons Third Lawd. Forcee. Weight

And give some explanations for the definition

2. A pendulum of mass 200 g is hung from ceiling with a light string. It is pulled horizontallywith another light string so that the pendulum makes an angle 30 with the vertical. Using

Newtons First Law, calculate the tensions in both of the strings.

3. An object of mass of 30 kg acted upon by a net force of 15 N will experience whatacceleration?

4. Three box connected by a rope of negligible mass are being dragged by a horizontal force, Fin figure given. Suppose that F= 400N, mA=10kg, mB=12kg, mC=7.5kg. Determine:

a. The acceleration of blocks systemb. The tension of the rope, TA and TB neglecting the friction between the floor and the

blocks

5. Two blocks, A of mass 10kg and B of mass 30kg, are side by side and in contact with eachanother. They are pushed along a smooth floor under the action of a constant force F ofmagnitude 200N applied to A. determine

a. The acceleration of the blocksb. The force exerted by A on B (FAB)

T1

T2

F

TB T

mC mB mA

F A

B

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6. Based on the two forces at a box of mass 20.0kg which is placed on a smooth surface asshown in figure given, determine the acceleration of the box.

7. A block of mass 200kg is pulled along an inclined plane of 30 by a force F=2kN as shown infigure. The frictional force, f exerted on the block is 200N. Determine:

a. The net force along the inclined plane surfaceb. The acceleration of the blockc. The time taken for the block to travel 30m from rest

8. A 0.30kg hockey puck slides on the horizontal frictionless surface of an ice rink. It is strucksimultaneously by two different hockey sticks. The two constant forces that act on thesurface are as shown in figure. The force F1has a magnitude of 5.0N and F2has a magnitude

of 8.0N.

a. Determine the acceleration of the puck while it is in contact with the two sticks.b. Determine the component of the third force that, when applied to the puck along

with the other two in Figure 1, causes the puck to have zero acceleration.

9. A 6.0kg object undergoes an acceleration of 2.0ms-1a. What is the magnitude of the net force acting on the object?b. If this same force is applied to a 4.0kg object, what acceleration does it produce?

10.A 1.80 x 103kg car is traveling in a straight line with a speed of 25.0ms-1. What is themagnitude of the constant horizontal force needed to bring the car to rest in a distance of80m?

11.A traffic light is weighing 122N hangs from a cable tied to two other cables fastened to asupport as in figure. The upper cables make angles of 37.0 and 53.0 with the horizontal.

These upper cables are not as strong as the vertical cables and will break if the tension inthem exceeds 100N. Does the traffic light remain in this situation or will one of the cables

break?

6 N 10 N

3040

F20

30

a

x

yF2

F1

20

60

T1 T2T3

37 53