# Total work done

#### fa08ti

A child on a sled (having a combined mass of 47.0 kg) is pulled by a force directed along a rope that makes a 45 degree angle with the horizontal axis. the force exerted on the rope is 100.00 N. the force of friction acting on the sled is 30.0 N. if the child is pulled a distance of 10.0 m along a level field, determine the total work done on the child and the sled.

Attempt:
Given:
d: 10.0 m, F:100.0 N (45 degrees), Ff: 30.0 N (180 Degrees)

W= 100.00 N X cos45 X 10.0m
W=707J
that would be just for the rope

would i have to do the same calculation using the Ff now? then add both numbers to get total work done?

It also asks for the final speed at the end of 10.0 m

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#### Doc Al

Mentor
would i have to do the same calculation using the Ff now? then add both numbers to get total work done?
Yes.

It also asks for the final speed at the end of 10.0 m
Make use of the net work done that you've calculated.

#### fa08ti

ok so for the speed, i'd use
W= (1/2)mv^2 and just rearrange it

Last edited:

#### Doc Al

Mentor
ok so for the speed, i'd use
W= (1/2)mv^2 and just rearrange it
Good!

#### fa08ti

thanks sooooo much. i've never taken physics before and i'm finding that while i understand most concepts, I tend to need a lot of reassurance

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