Two cars A and B are at rest at the same point initially. If A starts with uniform velocity of 40 m/sec and B starts in the same direction with a constant acceleration of 4 m/s², then B will catch A after how much time?

(1) 10 sec

(2) 20 sec

(3) 30 sec

(4) 35 sec

The motion of a particle is described by the equation $x=a+b{t}^2$ where a = 15 cm and b = 3 cm/s². Its instantaneous velocity at time 3 sec will be 

(1) 36 cm/sec

(2) 18 cm/sec

(3) 16 cm/sec

(4) 32 cm/sec

Consider the acceleration, velocity and displacement of a tennis ball as it falls to the ground and bounces back. Directions of which of these changes in the process ?

1. Velocity only

2. Displacement and velocity

3. Acceleration, velocity and displacement

4. Displacement and acceleration

The displacement of a particle, moving in a straight line, is given by $s=2t^2+2t+4$ where s is in metres and t in seconds. The acceleration of the particle is 

(1) 2 m/s²

(2) 4 m/s²

(3) 6 m/s²

(4) 8 m/s²

The velocity of a bullet is reduced from 200m/s to 100m/s while travelling through a wooden block of thickness 10cm. The retardation, assuming it to be uniform, will be  

(1) $10\times {10}^4$ m/s²

(2) $12\times {10}^4$ m/s²

(3) $13.5\times {10}^4$ m/s²

(4) $15\times {10}^4$ m/s² 

A student is standing at a distance of 50 metres from the bus. As soon as the bus begins its motion with an acceleration of 1 ms^–2, the student starts running towards the bus with a uniform velocity u. Assuming the motion to be along a straight road, the minimum value of u, so that the student is able to catch the bus is:

1. 5 ms^–1

2. 8 ms^–1

3. 10 ms^–1

4. 12 ms^–1

An object accelerates from rest to a velocity of 27.5 m/s in 10 sec . Then find the distance covered by the object in the next 10 sec:

(1) 550 m

(2) 137.5 m

(3) 412.5 m

(4) 275 m

Speed of two identical cars are u and 4u at a specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is:

(1) 1 : 1

(2) 1 : 4

(3) 1 : 8

(4) 1 : 16

A car, starting from rest, accelerates at the rate f through a distance S, then continues at a constant speed for time t and then decelerates at the rate $\frac{f}{2}$ to come to rest. If the total distance traversed is 15 S, then, 

(1) $S=\frac{1}{2}f{t}^2$

(2) $S=\frac{1}{4}f{t}^2$

(3) $S=\frac{1}{72}f{t}^2$  

(4) $S=\frac{1}{6}f{t}^2$ 

A man is 45 m behind the bus when the bus starts accelerating from rest with acceleration of 2.5 m/s². With what minimum velocity should the man start running to catch the bus?

1.  12 m/s
2.  14 m/s
3.  15 m/s
4.  16 m/s