1. An army vehicle of mass 1000 kg is moving with a velocity of 10 m/s and is acted upon by a forward force of 1000 N due to the engine and a retarding
force of 500 N due to friction. What will be its velocity after 10 s

a) 5 m/s

b) 10 m/s

c) 15 m/s

d) 20 m/s

Explanation:

2. A body of mass 2 kg is moving with a velocity 8 m/s on a smooth surface. If it is to be brought to
rest in 4 seconds, then the force to be applied is

a) 8 N

b) 4 N

c) 2 N

d) 1 N

Explanation:

3. The apparent weight of the body, when it is travelling upwards with an acceleration of \[2 m\diagup s^{2}\] and mass is 10 kg, will be

a) 198 N

b) 164 N

c) 140 N

d) 118 N

Explanation: R = m(g + a) = 10 * (9.8 + 2) = 118 N

4. A man measures time period of a pendulum \[\left(T\right)\] in stationary lift. If the lift moves upward with acceleration , \[\frac{g}{4}\]
then new time period will be

a) \[\frac{2T}{\sqrt{5}}\]

b) \[\frac{\sqrt{5}T}{2}\]

c) \[\frac{\sqrt{5}}{2T}\]

d) \[\frac{2}{\sqrt{5}T}\]

Explanation:

5. A 30 gm bullet initially travelling at 120 m/s penetrates 12 cm into a wooden block. The average resistance exerted by the wooden block is

a) 2850N

b) 2200 N

c) 2000N

d) 1800 N

Explanation:

6. A force of 10 Newton acts on a body of mass 20kg for 10 seconds. Change in its momentum is

a) 5 \[kgm\diagup s\]

b) 100 \[kgm\diagup s\]

c) 200 \[kgm\diagup s\]

d) 1000 \[kgm\diagup s\]

Explanation: dp = F*dt = 10 * 10 = 100 kg m/s

7. A body of mass 1.0kg is falling with an acceleration of \[10 m\diagup sec^{2}\] . Its apparent weight will be \[\left( g = 10 m\diagup sec^{2}\right)\]

a) 1.0kgwt

b) 2.0kgwt

c) 0.5kgwt

d) Zero

Explanation: R = m(g−a) = m(10−10) = zero

8. A player caught a cricket ball of mass 150 gm moving at the rate of 20 m/sec. if the catching process be completed in 0.1 sec the force of the
blow exerted by the ball on the hands of player is

a) 0.3 N

b) 30 N

c) 300 N

d) 3000 N

Explanation:

9. If rope of lift breaks suddenly, the tension exerted by the surface of lift (a = acceleration of lift)

a) mg

b) \[m\left(g+ a\right)\]

c) \[m\left(g- a\right)\]

d) 0

Explanation: If rope of lift breaks suddenly, acceleration becomes equal to g so that tension, T = m(g − g) = 0

10. A boy whose mass is 50kg stands on a spring balance inside a lift. The lift starts to ascent with an acceleration of \[2 m s^{-2}\] . The reading of the
machine or balance \[\left(g=10 m sec^{-2}\right)\]

a) 50 kg

b) Zero

c) 49 kg

d) 60 kg

Explanation: R = m(g + a) = 50 * (10 + 2) = 600 N = 60 kgwt