How do you determine work done wi th just mass and distance?

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Homework Help Overview

The problem involves calculating the work done when a person pushes a mass of 28 kg over a distance of 1.2 m. The original poster is attempting to understand how to arrive at the correct answer of 1200 J using the formula for work.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to use the work formula W=Fd and relates it to F=ma, leading to W=28a*1.2. They express confusion about the missing acceleration and how to reach the given answer. Other participants question the completeness of the problem, noting that additional information such as acceleration or final velocity is necessary to determine the work done accurately.

Discussion Status

The discussion is ongoing, with participants exploring the implications of missing information and questioning the assumptions made in the problem. Some guidance has been offered regarding the need for additional variables to solve the problem, but no consensus has been reached on a specific approach.

Contextual Notes

Participants note that the problem appears incomplete due to the lack of information about acceleration or final velocity, which are necessary to calculate the work done accurately.

crushedcorn
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1. The problem statement, all variables and given/Information

If a person pushes a 28 kg object 1.2 m, how much work did they just do?

Homework Equations


W=Fd
F=ma

The Attempt at a Solution


If W=Fd and F=ma, then W=(ma)d. The farthest I can get is W=28a*1.2=33.6a. Since the motion is horizontal, a=9.8 m/s2 wouldn't apply, so I am left with 2 variables and no answer. However, the correct answer is 1200 J. Where is this answer coming from?
 
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Out of the blue, as they say. Hello CC, and welcome to PF :smile: !

With the given information, there really is no telling. As you more or less conclude correctly.
There must be something else.
 
you would need atleast ##a## or final velocity. because for 1200J a= 35.7m/s², what if i choose a=1m/s². ill get a different answer.
So the question is incomplete.
 
Thank you and thank you! I felt like I was missing the entire concept. I feel much better :-)
 

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