A person is pulled to the right on a sled (total mass of 52.9 kg) across the surface of a frozen pond with a force of 67.7 Newtons so that they move with a constant velocity. What is the force of friction acting on the sled?

67.7 N

Explanation:

Draw a free body diagram of the person on the sled.  There are four forces:

67.7 N  to the right,

friction force to the left,

weight force down,

and normal force up.

Constant velocity means 0 acceleration.

Sum of the forces in the x direction:

∑F = ma

67.7 N − F = 0

F = 67.7 N

nah.   i'm just sleepy.