physics
posted by Alex .
A 6.0 kg mass moves along an inclined plane that makes an angle of 36 degrees with the horizontal. The mass is connected by a cable to a second mass of 10.0 kg, which is suspended over a frictionless, massless, pulley and is free to move. The second mass of 10.0 kg falls at a constant velocity. a) What are the magnitude and direction of the frictional force exerted by the 6.0 kg mass on the plane? b) What is the coefficient of kinetic friction between the 6.0 kg mass and the inclined plane?

The cable tension equals the weight of the 10 kg mass, since it falls at constant velocity.
For the 6 kg mass, the cable tension equals its weight component down the slope, minus the friction force.
Use that fact to solve for the friction force and coefficient. 
eachus?

A sign is attached to the side of a building using a beam and a cable. The sign weighs 430 pounds, and the angle between the cable and the beam is 20 degrees. You may ignore the weights of the beam and the cableuse only the weight of the sign in your calculations.