Does mass affect the amount of work done?

AI Thread Summary
The discussion centers on whether mass affects the amount of work done, defined by the equation W=F*s. It is clarified that work remains constant as long as the force and displacement are unchanged, regardless of mass. An example illustrates that moving a 4kg block and a 20kg block over the same distance with the same force results in the same work output. The confusion arises from the relationship between mass, force, and acceleration, where increasing mass leads to decreased acceleration but does not alter the work done if force remains constant. Ultimately, the key takeaway is that work is independent of mass when force and displacement are constant.
n124122
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Homework Statement


Is the amount of work depending on the mass?

Homework Equations


W=F*s
F=m*a

The Attempt at a Solution


attempt one:
because if you have a higher mass, it takes longer to make a certain object move over a certain distance, but it doesn't matter because time isn't measured. For example move a 4kg block over 3 meters with 6 Newton or move a 20 kg block over 3 meters with 6 Newtons, the work remains the same (3*6=18J).
Attempt two:
But when the mass is increased, in the formula F=m*a, the force is increased. So the work in the situation above should be increased? thereby making the work (20/4=5) 5 times bigger. What am i doing wrong?
 
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n124122 said:
attempt one:
because if you have a higher mass, it takes longer to make a certain object move over a certain distance, but it doesn't matter because time isn't measured. For example move a 4kg block over 3 meters with 6 Newton or move a 20 kg block over 3 meters with 6 Newtons, the work remains the same (3*6=18J).
Good. As long as the force and the displacement are the same, the work done will be the same.

n124122 said:
Attempt two:
But when the mass is increased, in the formula F=m*a, the force is increased. So the work in the situation above should be increased? thereby making the work (20/4=5) 5 times bigger. What am i doing wrong?
In the above, the applied force is kept the same. So when the mass is increased, the acceleration is decreased. But so what?
 
Doc Al said:
Good. As long as the force and the displacement are the same, the work done will be the same.In the above, the applied force is kept the same. So when the mass is increased, the acceleration is decreased. But so what?

thank you very much
 
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