Find the kinetic energy of the system

[milkyway11]

The question states: two adult bighorn rams butt heads in an elastic collision. the alpha male 136kg moves slower than his challenger that's 113kg. If the challenger collides at 8m/s and is repelled at 6m/s, find the kinetic energy of the system and the percent increase in speed that the alpha male experience.


I tried to solve the problem by using the conservation of momentum. However, since I don't know the initial nor final velocity of the alpha male, I decided to use the conservation of kinetic energy and find the Vi in terms of Vf. but that means I have to solve a v^2+v+c=0 (sorry, forgot what it was called). So i am not sure if i did it correctly since it is so complicated.

 

[tiny-tim]

hi milkyway11!

(try using the X² and X₂ icons just above the Reply box )

… in an elastic collision …

… I decided to use the conservation of kinetic energy …

"elastic" collision means that you must use conservation of energy (as well as conservation of momentum, which applies in all collisions)

… but that means I have to solve a v^2+v+c=0 (sorry, forgot what it was called). So i am not sure if i did it correctly since it is so complicated.

(it's a quadratic equation …)

it has to have two solutions, because one solution will always be for the two objects to completely miss each other, won't it?

 

[milkyway11]

Thank you for your reply!

hi milkyway11!

(try using the X² and X₂ icons just above the Reply box )


"elastic" collision means that you must use conservation of energy (as well as conservation of momentum, which applies in all collisions)


(it's a quadratic equation …)

it has to have two solutions, because one solution will always be for the two objects to completely miss each other, won't it?