Which of the following forces causes comets to regularly return to the inner solar system after being gone for many years? a. friction b. electromagnetic force c. magnetism d. gravity

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.