Question

A spool is pulled horizontally on a rough surface by two equal and opposite forces as shown in the figure. Which of the following statements is correct?

• A. The centre of mass moves towards left
• B. The centre of mass moves towards right
• C. The centre of mass remains stationary
• D. The net torque about the centre of mass of the spool is zero

Answer 1

The correct option is B

The centre of mass moves towards right

Net force on the spool is not zero, because the net torque due to the given forces is not zero, which makes the spool to rotate in clock -wise direction such that the point of contact tends to move left ward which in turn produces frictional force to act in right ward direction. So, centre of mass moves towards right due to the action of frictional force.