An object's mass is a measure of how much matter makes it up. An object's weight is a measure of the gravitational force that acts on it. An object's mass is always its weight.

Ablock having mass m slides down an inclined plane. the force of friction between the block and the inclined plane is f, the block's weight is m g, and the normal force is n. (a) draw a free – body force diagram showing the forces acting on the block. (b) write down all relevant newton’s equations for a given situation.