In the figure, a 700-kg crate is on a rough surface inclined at 30°. a constant external force p = 5600 n is applied horizontally to the crate. as the force pushes the crate a distance of 3.00 m up the incline, the speed changes from 1.40 m/s to 2.50 m/s. how much work does gravity do on the crate during this process?

Question

Christopher Hampton

Physics

9 February, 15:53

In the figure, a 700-kg crate is on a rough surface inclined at 30°. a constant external force p = 5600 n is applied horizontally to the crate. as the force pushes the crate a distance of 3.00 m up the incline, the speed changes from 1.40 m/s to 2.50 m/s. how much work does gravity do on the crate during this process?

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Casey Downs · Answer 1

This problem might be confusing since there are a lot of given variable but we must take note that the problem only asks about the Work done by gravity, therefore:

Work = - Potential Energy

Where,

Potential Energy = mass * gravity * height

Note: It is negative since it is gravity doing the work on our system, not work being done on gravity.

Since the surface is inclined at 30 degrees, therefore:

height = 3 m * sin 30

height = 1.5 m

Calculating for Work:

Work = - 700 kg * 9.8 m / s^2 * 1.5 m

Work = - 10,290 J

Work = - 10,300 J