Question

What happens to the motion of a body after some time, when the directions of its velocity and acceleration are opposite to each other?

• A. Velocity will increase continuosly till acceleration becomes zero.
• B. Velocity will decrease and body will come to rest.
• C. Velocity will decrease to zero, then it will start moving in the direction of acceleration.
• D. Velocity will be changing but it’s speed will be the same.

Answer 1

The correct option is C

Velocity will decrease to zero, then it will start moving in the direction of acceleration.

From first equation of motion,

$v=u+at$

If acceleration is negative, (i.e. acting in opposite direction to velocity)

$v=u-at$

So velocity will decrease in magnitude and eventually become zero, after which it will start moving in opposite direction.