Problem 83GP

Problem

A 65-kg ice skater coasts with no effort for 75 m until she stops. If the coefficient of kinetic friction between her skates and the ice is , how fast was she moving at the start of her coast?

Solution 83GP: We have to determine the initial velocity of the ice skater as she stops after covering a distance of 75m, due to presence of friction. Step 1 of 5 Concept: Newton’s second law: The net force F acting on an object of mass m produces an acceleration a in that object. Mathematically, F = ma. Frictional force also acts on the surface of the bodies in contact whenever their is relative motion between between the two bodies. Free body diagram of a body gives the diagrammatical representation of all the forces acting on the body in terms of magnitude and diagram, under the given situation. The kinematic equation relating the initial velocity (u)and final velocity (v) of an object, accelerating by an acceleration (a) in time (t) is given as, v = u + at