Question

A bulldozer does 4,500 J of work to push a mound of soil to the top of a ramp that is 15 m high. The ramp is at an

angle of 35° to the ground. How much force did the bulldozer apply to the mound of soil? Round your answer to two
significant figures.



Its 520 N

Answer 1

520 N

Step-by-step explanation:

Work is the dot product of the force vector and displacement vector.

W = F · x

This means it is the product of the magnitudes of the vectors and the cosine of the angle between them.

W = F x cos θ

The displacement of the soil is 15 m up. The force is parallel to the ramp. So the angle between the vectors is 90° − 35° = 55°.

Plugging in the values and solving for F:

4500 J = F (15 m) (cos 55°)

F = 523 N

Rounded to two significant figures, the force is 520 N.