On a cold winter day, a penny (mass 2.50 g) and a nickel (mass 5.00 g) are lying on the smooth (frictionless) surface of a frozen lake. With your finger, you flick the penny toward the nickel with a speed of 2.25 m/s . The coins collide elastically; calculate both their final speeds.What are the directions of their final velocities, opposite or the same?

Respuesta :

 cannot be done because they can deflect in various direction 
momentum is conserved. energy is changed to heat and sound "click" 
you could solve it it they were stuck in a straight line track 
no real collision is perfectly elastic 

did the penny go 2.25 hundred million miles and hour? pretty strong finger 
all problems need units