A 2000.-kg limousine moving east at 10.0 m/s collides with a 1000.-kg honda moving west at 26.0 m/s. the collision is completely inelastic an takes place on an icy (frictonless road) ?

Question

(a) find their common velocity after the collision
(b) what is the fractional loss in kinetic energy?

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Answer 1 · 2015-11-14T12:01:15

I found:
common velocity: $2m/s$ due west;
fractional loss: $72$

Have a look:
enter image source here

Kinetic Energy Before:
$K_b=1/2m_1v_1^2+1/2m_2v_2^2=1/2(2000)(10)^2+1/2(1000)(26)^2=$
$=100,000+338,000=438,000J$

Kinetic Energy After:
$K_a=1/2(m_1+m_2)v_f^2=1/2(3000)(-2)^2=6000J$

So:
$(K_b-K_a)/K_b=(438,000-6000)/6000=72$