Calculating Work Done by a Force on a Moving Object

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Homework Help Overview

The discussion revolves around calculating the work done by a force on a moving object, specifically a block being moved by a force of 85.0 N over a specified displacement from -3.00 cm to 5.00 cm.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the calculation of work using the formula W = F*S*cos(theta) and question the correctness of their displacement values and unit consistency.

Discussion Status

Multiple attempts to calculate work have been presented, with participants expressing uncertainty about their calculations and questioning the definitions of displacement and units. Some participants have suggested re-evaluating the calculations and checking for unit consistency.

Contextual Notes

There are indications of confusion regarding the displacement calculation and the proper use of units, as well as a sense of frustration from one participant about the progress of the discussion.

Abarak
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Homework Statement


Find the work W done on the block by the force of magnitude F = 85.0N as the block moves from xi = -3.00cm to xf = 5.00cm.

Homework Equations


W = F*S*cos(theta)

The Attempt at a Solution


W = (85.0N)(-3cm-5cm)*1
W = -260J

Am I missing something?
 
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The definition of displacement.
 
And a consistent set of units
 
Let me try this again...

W = (85.0N)(3cm+5cm)*1
W = 680J

(3cm + 5cm) because the block is moving from -3cm to 0 and from 0 to 5cm. This gives us a grand total of 8cm the block was moved. Sorry for the rather rudimentary question.
 
Abarak said:
W = (85.0N)(-3cm-5cm)*1
W = -260J

Am I missing something?

a calculator??
and check the units
Newton * meter = joule
 
God, that was terrible. I'm going to stop right now and start again tomorrow. Sorry for the waste of time.
 

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