Bob, who has a mass of 80 kg, can throw a 460 g rock with a speed of 26 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.2 m.
a)What constant force must Bob exert on the rock to throw it with this speed?
(b) If Bob is standing on frictionless ice, what is his recoil speed after releasing the rock?