A 40-Kg Block Is Lowered Down a 37° Incline a Distance

Multiple Choice

A 4.0-kg block is lowered down a 37° incline a distance of 5.0 m from point A to point B. A horizontal force (F = 10 N) is applied to the block between A and B as shown in the figure. The kinetic energy of the block at A is 10 J and at B it is 20 J. How much work is done on the block by the force of friction between A and B?

A) −58 J
B) −53 J
C) −68 J
D) −63 J
E) −47 J