A body moves from rest with a constant acceleration of 5 m/s2. Its instantaneous speed (in m/s) at the end of 10 sec is
(1) 50
(2) 5
(3) 2
(4) 0.5
If a car at rest accelerates uniformly to a speed of 144 km/h in 20 s. Then it covers a distance of
(1) 20 m
(2) 400 m
(3) 1440 m
(4) 2880 m
If a train travelling at 72 kmph is to be brought to rest in a distance of 200 metres, then its retardation should be
(1) 20 ms–2
(2) 10 ms–2
(3) 2 ms–2
(4) 1 ms–2
The displacement of a particle starting from rest (at t = 0) is given by . The time in seconds at which the particle will attain zero velocity again, is
(1) 2
(2) 4
(3) 6
(4) 8
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 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 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) m/s2
(2) m/s2
(3) m/s2
(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