A block is projected with speed v across a horizontal surface and slides to a stop due to friction. The same block is then projected with the same speed v up an incline where it slides to a stop due to friction. In which case did the total mechanical energy of the block decrease the least?
A) This problem cannot be solved since it was not indicated whether the horizontal surface and the incline both had the same coefficient of kinetic friction.
B) The case on the horizontal surface had the least decrease in total mechanical energy.
C) The case on the inclined surface had the least decrease in total mechanical energy.
D) In both cases the decrease in mechanical energy was the same.

Question

Quizplus · Accepted Answer

The work done by friction is less on the incline because the normal force is less than on the horizontal surface.

A Block Is Projected with Speed V Across a Horizontal