Work constant velocity

  • Thread starter nbroyle1
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  • #1
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You are pushing a refrigerator across the floor of your kitchen. You exert a horizontal force of
291N for 7.5s, during which time the refrigerator moves a distance of 2.7m at constant velocity.

(a) What is the total work (by all forces) done on the refrigerator?

(b) What is the work done by friction?

How can I calculate the work done by friction if a mass isn't provided and there is no acceleration obviously since there is a constant velocity?
 

Answers and Replies

  • #2
tiny-tim
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welcome to pf!

hi nbroyle1! welcome to pf! :smile:
How can I calculate the work done by friction if a mass isn't provided and there is no acceleration obviously since there is a constant velocity?

that's right, the acceleration is zero and the velocity is constant …

so use the work energy theorem :wink:
 
  • #3
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Thanks, but don't I need the mass for the work energy theorem also?

Net work=1/2mv(final)^2-1/2mv(initial)^2
 
  • #4
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Is the friction force equal to the force applied since it is a constant velocity? or would that just meant that the object isn't moving at all?
 
  • #5
tiny-tim
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(try using the X2 button just above the Reply box :wink:)

in this case, 1/2mv(final)2-1/2mv(initial)2 = … ? :smile:
 
  • #6
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doesnt it just equal zero since the velocity is the same?
 
  • #7
tiny-tim
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Is the friction force equal to the force applied since it is a constant velocity?

yes :smile:

(lots of exam questions are exactly like this)
 
  • #8
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Ok awesome thanks!!!
 

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