Question

The force (F) required to keep the body moving at a constant speed of 3 m/s is ______.

• A. 0 N
• B. 5 N
• C. 10 N
• D. 15 N

Answer 1

The correct option is C 10 N

To maintain a constant speed of 3 m/s, the net force acting on the body must be zero.

There are only two forces acting on this block, namely, frictional force which is acting towards left since it opposes relative motion, and force F which is acting towards right.

Since net force is zero, F - 10 = 0
F = 10 N

So to maintain a constant speed, force required is 10 N towards right.