What is the stored energy of a wind-up watch?

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A person does 0.02 Joules of work winding a watch, and assuming no energy loss to friction, this work is entirely converted into potential energy stored in the watch's mainspring. The relevant equation for potential energy, PE = 1/2kx^2, is acknowledged, but not necessary for this problem. The key concept discussed is the conservation of energy, confirming that all work done translates directly to stored energy. The conclusion is that the energy stored in the watch's mainspring is 0.02 Joules. This understanding emphasizes the relationship between work and energy in mechanical systems.
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Homework Statement


A person does .02 Joules of work winding a watch. Assuming NO loss of energy to friction, how much energy is stored in the watch's main spring?

Homework Equations


PE=1/2kx^2 ?? I have no idea..

The Attempt at a Solution


I've gotten nowhere trying to do this problem without other information, such as mass or length.

Thank you for looking and helping!
 
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kelcijade said:

Homework Statement


A person does .02 Joules of work winding a watch. Assuming NO loss of energy to friction, how much energy is stored in the watch's main spring?


Homework Equations


PE=1/2kx^2 ?? I have no idea..


The Attempt at a Solution


I've gotten nowhere trying to do this problem without other information, such as mass or length.

Thank you for looking and helping!

Welcome to the PF.

Hint -- what are the units of energy?
 
Also crucial- conservation of energy since there is no friction. Don't use a formula- think.
 
The unit of energy is just Joules.. Right? Well in this case.

So would it just be a potential energy of .02J since the total work done is calculated by the Newtons of force and meters which they don't give in the problem?
 
kelcijade said:
The unit of energy is just Joules.. Right? Well in this case.

So would it just be a potential energy of .02J since the total work done is calculated by the Newtons of force and meters which they don't give in the problem?

Correct. As Halls alludes to, since there is no energy lost to friction, all of the work has to go into storing potential energy in the spring. Good job!
 
berkeman said:
Correct. As Halls alludes to, since there is no energy lost to friction, all of the work has to go into storing potential energy in the spring. Good job!

Thank you both!
 

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