AAMC 3R P/S #77

[deleted783484]

Answer key:
Work is the product of force and distance. The easiest way to calculate the work in this pulley
problem is to multiply the net force on the weight mg by the distance it is raised: 4 kg x 10 m/s2 x
5 m = 200 J. Therefore, answer choice D is the best answer.

@aldol16 why are they not taking into account sin and cos? Thank you!

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[5words]

Because the angle doesn't matter in pulleys. Like the work done to pull an object of mass m , under a gravitational field g, in any pulley will always be W = mg * d regardless of the angle at which the cord is being pulled. Thus the work done to pull these blocks will be the same.