Asprain .. a) is the most painful of all athletic injuries. b) is an injury that can never be healed. c) can be completely avoided by stretching. d) is a stretch and/or tear of a ligament.

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.