A 20.0 kg box slides up a 12.0 m long incline at an angle of 30.0 degrees with the horizontal.A force of 150 N is applied to the box to pull it up the incline.The applied force makes an angle of 10.0 degrees to the incline.What is the change in gravitational potential energy,in Joules?
A) 2,570
B) 2,350
C) 1,450
D) 1,180
E) 945

Question

Quizplus · Accepted Answer

The first step is to find the component of the force parallel to the incline:
150 N * sin(10°) = 25.9 N
Next, we can find the work done by this force:
W = F*d*cos(θ)
W = 25.9 N * 12.0 m * cos(30°)
W = 298.4 J
Finally, we can use the work-energy theorem to find the change in gravitational potential energy:
ΔPE = W
ΔPE = 298.4 J, which is closest to choice D (1,180 J).

A 200 Kg Box Slides Up a 12