Multiple Choice
In the figure, a 900-kg crate is on a rough surface inclined at 30°. A constant external force
P = 7200 N is applied horizontally to the crate. While this force pushes the crate a distance of 3.0 m up the incline, its velocity changes from 1.2 m/s to 2.3 m/s. How much work does friction do during this process? 
A) -3700 J
B) -7200 J
C) +3700 J
D) +7200 J
E) zero
Correct Answer:

Verified
Correct Answer:
Verified
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