Calculating Horse Power: How Many Bundles of Shingles Can a Horse Hoist?

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A horse capable of maintaining 1.00 horsepower for 2 hours, at 70% efficiency, can hoist approximately 684 bundles of 70 kg shingles to an 8-meter high roof. The calculations confirm that the horse's output translates to about 3,758,328 joules of work. The work required to lift one bundle of shingles is calculated at 5,488 joules. The discussion emphasizes the importance of understanding animal capabilities in relation to physical tasks. This calculation illustrates the significant workload a horse can handle.
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If a certain horse can maintain 1.00hp of output for 2 hrs, how many 70 kg bundles of shingles can the horse hoist to the roof of a house 8 m tall, assuming 70% efficiency?

He're what I did: 1 hp = 745.7 W = 44742 J/min = 2684520 J/hr = 5369040 J/ 2 hr * 70% = 3758328 J / 2 hr

W=Fd
W=(70*9.8)(8m)
W=5488 J

3758328 J / 5488 J =684.8 bundles of shingles

is this correct?
 
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The working is right - so if u calculated the numbers properly - you should get the right answer.
 


Yes, your calculation is correct. According to your calculation, a horse with 1.00hp of output for 2 hours and 70% efficiency can hoist approximately 684 bundles of shingles to the roof of a house 8m tall. This is a significant amount of work for a single horse! It is important to consider the weight and physical capabilities of animals when determining the amount of work they can perform, and this calculation is a good example of that. Great job!
 

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