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Momentum/impulse - kinetic energy

A truck of mass 10 tonnes moving at 2.4 ms-1 collides with a 5 tonne stationary truck. Following the impact the relative velocities of the trucks is 0.6 ms-1. Determine the kinetic energy lost in the collision.

i forgot the kinetic loss equation got me the wrong answer. needed to check if we work out V1 first and then sub into the kinetic loss equation and whats the kinetic loss equation??
Reply 1
Kinetic before = Kinetic after+ Kinetic Energy Lost
0.5*10000*2.4^2 + 0 = (0.5*5000*0.6^2 + 10000*0.5*0.6^2) + Energy Kinetic lost.
28800 = 2700 + Energy Lost
28800-2700 = Energy Lost
26100 Joules.

Is this right?
Reply 2
Original post by arjunthedon
Kinetic before = Kinetic after+ Kinetic Energy Lost
0.5*10000*2.4^2 + 0 = (0.5*5000*0.6^2 + 10000*0.5*0.6^2) + Energy Kinetic lost.
28800 = 2700 + Energy Lost
28800-2700 = Energy Lost
26100 Joules.

Is this right?


I dont know, because i dont understand the meaning on relative velocities and how the final velocites of both trucks changes.

In the calculation above you have stated that both final velocities is 0.6 and somehow they will be moving together.

Someone confirm please?

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