How much mechanical work was done by 2 men lifting a boat 24 times?

AI Thread Summary
Two men lifted a boat weighing 653.2 kg a height of 4 inches (0.102 meters) a total of 24 times. The total force exerted was calculated as 6401 Newtons after converting the mass. Using the work formula (w = f * d), the initial calculation resulted in 15672 Joules, but the textbook answer is 2x10^4 Joules. The discrepancy arises from the need to round the final answer to one significant digit due to the height measurement. The correct total mechanical work done, when rounded appropriately, is indeed 2x10^4 Joules.
maxdaddy
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Homework Statement



2 men lift a total mass of 653.2 kg 4in off the ground a total of 24 times. Estimate the total mechanical work done by the 2 men in lifting the boat 24 times, assuming they applied the same force to the boat during each lift. (Neglect any work they may have done allowing the boat to drop back to the ground.)

Homework Equations


w=f*d


The Attempt at a Solution


w=f*d
First convert kg to Newtons 653.2*9.8=6401N and inches to meters 4in=.102m
I tried the f*d and came up with 653 and then multiplied that by 24 and got 15672. The answer in the back of the textbook gives 2x10^4 J and I cannot figure it out.
 
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I suppose you are expected to give the answer with only one significant digit. The height (4 in) has only one digit so the answer should have one SD too.
 
nasu said:
I suppose you are expected to give the answer with only one significant digit. The height (4 in) has only one digit so the answer should have one SD too.

No if you read my post the answer the textbook gives is 2*10^4J and I cannot figure out how to get the answer
 
maxdaddy said:
No if you read my post the answer the textbook gives is 2*10^4J and I cannot figure out how to get the answer

Your answer it is 2x10^4 if you round it to one significant digit.
 
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