If Jocko has a mass of 60 kg and stands at rest on ice catches a 20 kg ball that is thrown to him at 10 kmh How fast does Jocko and the ball move across the ice?

Answer 1

force = mass x acceleration

force = mass x (distance/sec2)

force x distance = mass x (distance2/sec2) force x distance= work done (energy)

energy = mass x velocity2 10km/h = 10000m/h = 166and 2/3 m/s

energy as ball hits person on ice = 20 x 166.672 = 555577.778Joules

now energy is neither created nor destroyed it is simlply transferred from one form to another

assuming ice has no friction then

555577.778= newmass x velocity2

velocity2 = 555577.778/80 = 6944.722225

velocity = 83.335m/s = 5000.1m/h = 5km/h

Answer 2

According to the law of conservation of momentum, the total momentum before the catch should equal the total momentum after the catch. Since the initial momentum of the ball is 200 kgm/s, the final momentum after the catch will also be 200 kgm/s shared between Jocko and the ball. The final velocity can be calculated using momentum = mass * velocity. Jocko and the ball will move across the ice at the same final velocity.