Posted by alissa on .
work & energy homework problems:
please help me =] my teacher is bad a teaching how to do stuff =/
1)A 5.000kg plastic ball moves with a velocity of 10.00 m/s x. It collides with a second plastic ball of mass of 10.00kg at rest. The collision is completely elastic. find:
a)the initial kinetic energy of the system.
b)the final kinetic energy of the system.
c)the initial momentum of the system.
d)the final momentum of the system.
e)the final velocity of the system.
f)the final velocity of the system.
& the formula for kinetic energy is KE=1/2 mass*velocity squared

physics 
drwls,
(a) (1/2)M1 V1^2 = 250 J
(b) Same nummber, since the collision is elastic
(c) M1 V1 = 50 kg m/s
(d) same number, since momentum is always conserved
(e,f) Are you asking the last questions correctly? The two masses end up with different velocities. There is no "system velocity". It is possible to solve for the separate velocities of M1 and M2.