Question

Which of the following statements are correct?

• A. If a body is in motion, then no force is acting on it.
• B. If the acceleration of a body is zero, then the body is at rest.
• C. If a body is at rest, there must be some non-zero force to keep it at rest.
• D. If a body remains at rest, then the net force acting on it must be zero.

Answer 1

The correct option is D If a body remains at rest, then the net force acting on it must be zero.

According to newton's first law,
"A body at rest remains at rest or, if in motion , remains in motion at constant velocity unless acted on by a net external force."
Hence option D is correct.
Note that it is possible for an object to be in motion with no force acting on it.