Kinetic energy: what percentage has been lost?

[totentanz777]

Homework Statement

So there's a particle of mass 4u that strikes another particle of mass 196u. The collision is elastic. What percentage of its original kinetic energy has the moving particle lost?

Homework Equations

m1v1o + m2v2o = m1vf + m2v2f
K1o + K2o = K1f + K2f

The Attempt at a Solution

so because its elastic, the kinetic energy total will not change, thus the Kt= Kft.
V2o will be zero, because its not moving. It is possible to set the two equations, one for momentum and the other for Kinetic Energies, equal to each other and cancel out v2f. This helps reduce the problem to
24Vo^2 + VoVf = 25Vf^2
how would having this equation help me find the percentages? Am I on the right track at all?

 

[SammyS]

Homework Statement

So there's a particle of mass 4u that strikes another particle of mass 196u. The collision is elastic. What percentage of its original kinetic energy has the moving particle lost?

Homework Equations

m1v1o + m2v2o = m1vf + m2v2f
K1o + K2o = K1f + K2f

The Attempt at a Solution

so because its elastic, the kinetic energy total will not change, thus the Kt= Kft.
V2o will be zero, because its not moving. It is possible to set the two equations, one for momentum and the other for Kinetic Energies, equal to each other and cancel out v2f. This helps reduce the problem to
24Vo^2 + VoVf = 25Vf^2
how would having this equation help me find the percentages? Am I on the right track at all?

If the collision is head-on, then yes, the problem can be solved.

What is K1_F/K1₀ ?