A 16.0-N weight slides down a rough inclined plane that makes an angle of 28.0° with the horizontal. The weight, which started from rest, gains a speed of 15.0 m/s after sliding 150 m. How much work is done against friction?

Answer 1

use the work-energy theorem

determine mass = 16.0N/9.8 m/s^2
initial velocity = 0; so initial KE = 0
final velocity = 15.0 m/s
final height = 0; so final PE = 0
initial height = 150 sin 28.0 degrees

substitute values in the work-energy theorem expression