## A body has zero velocity and still be accelerating ?

Q: Which statements can be possible cases in one/two dimensional motion: (A) A body has zero velocity and still be accelerating (B) The velocity of an object reverses direction when acceleration is constant (C) An object be increasing in speed as its acceleration decreases    (D) None of these   Solution : (a) When the body […]

## A particle is moving along a circular path of radius 5m and with uniform speed 5 m/s. What will be the average acceleration when the particle completes half revolution

A particle is moving along a circular path of radius 5m and with uniform speed 5 m/s.  What will be the average acceleration when the particle completes half revolution? (A) zero (B) 10 m/s2 (C) 10 π m/s2 (D) 10/π m/s2 Solution :  The change in velocity when the particle completes half revolution is given […]

## A driver applies the brakes on seeing traffic signal 400 m ahead. At the time of applying the brakes vehicle was moving with 15 ms-1 and retarding with 0.3 ms-2. The distance of vehicle after 1 min from the traffic light

A driver applies the brakes on seeing traffic signal 400 m ahead. At the time of applying the brakes vehicle was moving with 15 ms-1 and retarding with 0.3 ms-2. The distance of vehicle after 1 min from the traffic light: (A)  25 m (B)  375 m (C)  360 m (D)  40 m Solution : The […]

## A car is moving eastwards with velocity 10 m/s. In 20 sec, the velocity changes to 10 m/s northwards. The average acceleration in this time

Q:A car is moving eastwards with velocity 10 m/s. In 20 sec, the velocity changes to 10 m/s northwards. The average acceleration in this time: (A)1/√2 m s-2 towards N-W (B)1/√2 ms-2 towards N-E (C) 1/2 m s-2 towards N-W (D) 1/2 ms-2 towards N Solution: The change in velocity is Δv = v2 – v1 = 10j – […]

## If an object travels one-half its total path in the last second of its fall from rest, find (a) the time and (b) the height of its fall

If an object travels one-half its total path in the last second of its fall from rest, find (a) the time and (b) the height of its fall. Explain the physically unacceptable solution of the quadratic time equation. [ Ans: (a) 3.4 sec  (b) 57m ]