Can the final kinetic energy of the system be greater than the initial KE in a collision?

Asked by devanshu_jain | 23rd Oct, 2010, 02:40: PM

Expert Answer:

Dear student
Following account would help you undertsand how Kinetic energy modifies post collision.

In Completely Inelastic Collisions

The ratio of final to initial kinetic energy is

K2⁄K1 = mA(mA + mB), (completely inelastic collision, B initially at rest).

The right side is always less than unity because the denominator is always greater than the numerator. Even when the initial velocity mB is not zero, it is not hard to verify that the kinetic energy after a completely inelastic collision is always less than before.

In Completely Elastic Collisions

If the kinetic energy of a system is the same after the collision, we call this kind of collision elastic collision.

The ratio is unity here.

We hope that resolves your query.




Answered by  | 25th Oct, 2010, 09:48: AM

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