Question

In which of the following cases forces may not be required to keep the
a) particle going in a circle
b) particle going along a straight line
c) momentum of the particle constant
d) acceleration of the particle constant​

Answer 1

Explanation:

Force is the rate of change in momentum,

F= dP/dt. (p is momentum)

p=mv

If the rate of change in momentum is zero or momentum is constant then net force acting on the body is zero

F= dp/dt =0 when P is constant or zero