posted by Lisa .
You push a 320 N trunk up a 20.0° inclined plane at a constant velocity by exerting a 213 N force parallel to the plane's surface.
(a) What is the component of the trunk's weight parallel to the plane?
(b) What is the sum of all forces parallel to the plane's surface?
(c) What is the magnitude and direction of the friction force?
upward, perpendicular to the plane
upward along the plane
downward, perpendicular to the plane
downward along the plane
(d) What is the coefficient of friction?
You need to try to grunt through this yourself. I will be happy to critique your thinking.
What force would you have to exert on a 326-N trunk up a 21.0° inclined plane so that it would slide down the plane with a constant velocity? What would be the direction of the force? (The coefficient of friction between the plane and the trunk is 0.329.)