physics
posted by Mel .
A block weighing 8.3 N requires a force of 2.6 N to push it along at constant velocity. What is the coefficient of friction surface?
A weight W is now placed on the block and 8.2 is needed to push them both at constant velocity. What is the weight W of the block? answer in units of N.

The coefficient of kinetic friction is the ratio
(force required to pull)/weight
= 2.6/8.3 = 0.313
With added weight W,
8.2 = 0.313(8.3 + W)
26.2 = 8.3 + W
W = 17.9 N 
A dockworker applies a constant horizontal force of 71.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 11.0 m in a time 5.40 s. What is the mass of the block of ice?

uh huh