The pucks A, B and C are sliding across ice at given speeds. The pucks have different masses, and forces of air and ice friction are negligible. Puck A: 5 m/s, 2 kg Puck B: 10 m/s, 1 kg Puck C: 12 m/s, 10 kg

a) Use symbols to rank the pucks by the magnitude of the force needed to stop them in the same time invterval.

b) Use symbols to rank the pucks by the magnitude of the force needed to keep them moving.