Question

A force F is exerted on a 5 kg block to move it across a rough surface, as shown above. The magnitude of the force is initially 5 N, and the block moves at a constant velocity. While the block is moving, the force is instantaneously increased to 12 N. How much kinetic energy does the block now gain as it moves a distance of 2 m?

Answer 1

Step-by-step explanation:

The work done by a constant force is given by the equation W = Fd, where W is the work done, F is the force, and d is the distance moved.

The initial force of 5 N does no work, because it is balanced by the friction force. So, the work done by the increased force of 12 N can be found as follows:

W = Fd = 12 N x 2 m = 24 J

The work done on an object is equal to the change in its kinetic energy, so the increase in the block's kinetic energy is 24 J.