Step-by-step explanation:
Given that,
A girl pushes her little brother on his sled with a force of 200. N for 850. m
We need to find the work done by the force of friction acting on the sled. The force of friction is 200 N
Net force = 200 N - 200 N = 0
Work done = 0
If force of friction is 300 N.
Net force = 300 N - 200 N = 100 N
The work done by a force is given by :
W = Fd
Put values,
W = 100 × 850
W = 85000 J
Hence, this is the required solution.