Your job is to lift 30-kg crates a vertical distance of 0.90 m from the ground onto the bed of a truck. How many crates would you have to load onto the truck in one minute for the average power output you use to lift the crates to equal 0.50 hp?(adsbygoogle = window.adsbygoogle || []).push({});

The equation that I used is: P_av = (delta W)/ (delta t)

Since 1hp = 746W --> 0.50hp = 373 W

delta W = (P_av)(delta t) = 373 W x 60 s = 22380 J

Work required to lift one crate = mgh = 30kg x 9.8 m/s^2 x 0.9m = 264.6J

Number of crates = 22380J / 264.6 J = 85

85 is not the correct answer. What did I do wrong?

Thanks.

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# Homework Help: Working Like a Horse

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