How much work is done on a bucket when pulling it up?

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Homework Help Overview

The problem involves calculating the work done on a bucket being pulled up a well, focusing on the forces acting on the bucket and the work-energy principle. The subject area includes mechanics, specifically work and energy concepts.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to apply the work formula and considers the equilibrium of forces acting on the bucket. They express confusion regarding a discrepancy between their calculated work and the answer provided in the textbook.

Discussion Status

Some participants affirm the original poster's calculation, suggesting that there may be an error in the textbook's answer key. The discussion reflects differing interpretations of the problem's requirements.

Contextual Notes

Participants are discussing the implications of the bucket moving slowly and the assumption of equilibrium, as well as the potential for errors in the provided answer key.

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Homework Statement


An old oaken bucket of mass 6.75 kg hangs in a well at the end of a rope. The rope passes over a frictionless pulley at the top of the well, and you pull horizontally on the end of the rope to raise the bucket slowly a distance of 4.00m.
A). How much work do you do on the bucket in pulling it up?

Homework Equations


##W = FS##
##W = ΔKE##
##ΣFy = T - mg##

The Attempt at a Solution


First, I assumed the problem was implying that the bucket was in equilibrium when it said it was moving slowly. So since the weight is ##(9.81)(6.75) = 66.21 N##, the tension force must be equal to that.

So, ##W = FS##. ##W = (66.21)(4) = 264.84 J##. This seemed like the correct answer to me, but when I look at the back of the book, it says the answer is 3.60 J.

Where did I go wrong here? Thanks!
 
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I'd say your answer is correct. What book/problem is this from?
 
Doc Al said:
I'd say your answer is correct. What book/problem is this from?
That's what I thought too. It's from "Sears and zemansky's University Physics With Modern Physics, 12th edition".

I guess there was a mistake or something in the answer key.
 
BlueQuark said:
I guess there was a mistake or something in the answer key.
Yep.
 

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