Respuesta :

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.