Calculating Work Done on Child & Sled Pulled by Force

AI Thread Summary
To calculate the total work done on a child and sled being pulled, the force exerted along the rope at a 45-degree angle is 100.00 N, and the force of friction is 30.0 N. The work done by the pulling force is calculated using W = F(cosθ) * d, resulting in 707 J for the rope. The force of friction also needs to be considered, requiring a similar calculation to find its contribution to the total work. To determine the final speed after pulling the sled 10.0 m, the net work done can be used with the formula W = (1/2)mv². Understanding these calculations is essential for solving physics problems involving work and motion.
fa08ti
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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=F(costheta) . deltad
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

HELP PLEASE!
 
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fa08ti said:
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.
 
ok so for the speed, i'd use
W= (1/2)mv^2 and just rearrange it
 
Last edited:
fa08ti said:
ok so for the speed, i'd use
W= (1/2)mv^2 and just rearrange it
Good!
 
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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