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MikeMM
Apr 2, 2008, 07:09 PM
A worker pushes a 1500 Newton crate with a horizontal force of 345 Newtons a distance of 24.0 meters. Assume the coefficient of kinetic friction between the crate and the floor is 0.220.
a.) How much work is done by the worker on the crate?
b.) How much work is done by the floor on the crate?
c.) What is the net work done on the crate?

I know I need to use the equation Work=Force x Distance but how do I calculate for the separate two?

Cho
Apr 7, 2008, 08:24 AM
Assuming 345 is a horizontal force.
Work done by the man = F.S
= (345 - 0.22 x 1500) x 24
where 0.22 x 1500 is the frictional force which is the product of coeeficient of friction and the reaction of the floor.

Work done by floor = F.S
= F S cos90 (since angle between reaction and motion is 90)
=0

Total work done is the work done by the man alone.

Hope this is the correct ans. double check