Question

a block slides on a rough horizontal surface from point a to point b. a force with magnitude acts on the block between a and b, as shown. points a and b are 10 m apart. if the kinetic energies of the block at a and b are 15 j and 7 j respectively, how much work is done on the block by the force of friction as the block moves from a to b?

Answer 1

The work done by the force of friction is -8J.

Step-by-step explanation:

The work done by the force of friction can be calculated using the equation:

Work = Change in Kinetic Energy

Here, the kinetic energy of the block at point A is 15J and at point B is 7J. The change in kinetic energy is:

Change in Kinetic Energy = Kinetic Energy at B - Kinetic Energy at A = 7J - 15J = -8J

Since work is equal to the change in kinetic energy, the work done on the block by the force of friction as it moves from point A to point B is -8J.