Question

Which of the following can depict an object undergoing uniform motion.
1. A force of 20N applied on left and right direction (both is 20N).
2. An upward force of 5N and downward force of 25N.

Answer 1

Answer:(1)

Explanation:Because in uniform motion net external force must be zero.

Answer 2

Option 1 is right if body is already moving with a velocity and there is no friction on the body of any kind.

Explanation:

option 1 is right because in both the directions there is a force applied 20 N of equal magnitude. The all together reaction is nil because they cancel each other.

There is no overall effect on the body as they cancel each other. Body will move with same uniform velocity.

In second case there is 20 N net force acting on the body which accelerates the body and velocity will not be uniform.