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 only till the object comes to rest.
• C. Velocity will decrease to zero, then it will start moving in the direction of acceleration.
• D. Velocity will be changing but its 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,

$v=u+at$ , where u is the initial velocity, v is the final velocity attained and a is the constant acceleration
If acceleration is negative, $v=u-at$

So, velocity will decrease in magnitude and eventually become zero, after which the body will start moving in the direction of acceleration.