Question

Object A has of mass 7.20 kilograms, and object B has a mass of 5.75 kilograms. The two objects move along a straight line toward each other with velocities +2.00 meters/second and -1.30 meters/second respectively. What is the total kinetic energy of the objects after the collision, if the collision is perfectly elastic?

19.3 joules
21.9 joules
38.5 joules
43.0 joules
50.8 joules

Answer 1

19.3

Step-by-step explanation:

Just a quick answer the other guy says the same thing

Answer 2

since the collision is elastic the kinetic energy in the beginning is the same after the collision. K1+K2. kinetic energy is given by
`(1)/(2)m v^(2)`
The total is given by

`(1)/(2) m_(1) ( v_(1) )^(2)+ (1)/(2) m_(2) ( v_(2) )^(2)`
This gives 19.26J. So the first answer looks to be the right one