question_answer

When torque acting upon a system is zero which of the following will be constant?

A)  Force                                   

B)  Linear momentum

C)  Linear impulse                 

D)  None of the above

Correct Answer: D

Solution :

                 When an external force acting on a body has a tendency to rotate the body about an axis, then the force is said to exert a torque upon the body about that axis. The moment of a force or torque about an axis of rotation is equal to the product of the magnitude of the force and perpendicular distance of the line of action of force from the axis of rotation. \[\tau =r\times F\]