# Work and Kinetic Energy of barrel (1 Viewer)

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#### ScienceGirl90

1. The problem statement, all variables and given/known data
A 45.0 kg barrel is raised 6.60 m (from rest) by cable that exerts 710 N on the barrel. Neglecting any frictional energy losses, how much work is done against gravity to lift the barrel and what is the net work done on the barrel?

2. Relevant equations
W=m*g*h
W=F*D

3. The attempt at a solution
I am confused about the wording, "against gravity". Also when I tried to find the net work done on the barrel I did W=(45.0kg)(9.80m/s/s)(6.60m)= 2910 J. Is that right?

#### The legend

against gravity means you are lifting the object, opposing the action of gravity.
So your W(net) = W(grav) + W(cable)

now apply W=mgh for both cases, (keeping in mind the signs), and add them to get your net work.

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