Which best describes nuclear fission? a. a nucleus spontaneously splits and absorbs energy. b. two nuclei spontaneously combine and absorb energy. c. a nucleus collides with a neutron and splits, releasing energy. d. nuclei combine to form a heavier nucleus, releasing energy.

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.