Answer:
The work done on the sled by friction, W = - 4593.75 J
Explanation:
Given data,
The combined mass of sled and the boy, m = 75 kg
The displacement of the boy, S = 25 m
The coefficient of the friction, u = 0.25
The frictional force acting on the boy,
<em>F = u η</em>
Where,
η - is the normal force acting on the boy (mg)
Substituting the values,
F = 0.25 x 75 x 9.8
= 183.75 N
Since the direction of the frictional force is against the direction of motion
F = - 183.75 N
The work done on the sled by friction,
W = F x S
= - 183.75 x 25
= - 4593.75 J
Hence, the work done on the sled by friction, W = - 4593.75 J