Kinetic Energy Exploding Question

AI Thread Summary
An object with a mass of 79 kg and a speed of 23 m/s explodes into two pieces, one five times as massive as the other, with the less massive piece stopping relative to the observer. The discussion highlights that while kinetic energy is not conserved due to the explosion adding energy, momentum is conserved. Participants suggest using momentum to determine the final velocities of both pieces after the explosion. The final kinetic energy can then be calculated, and the difference between the initial and final kinetic energy will reveal the energy added during the explosion. This approach effectively addresses the problem of calculating the kinetic energy added to the system.
shell4987
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Homework Statement


An object, with mass 79 kg and speed 23 m/s relative to an observer, explodes into two pieces, one 5 times as massive as the other; the explosion takes place in deep space. The less massive piece stops relative to the observer. How much kinetic energy is added to the system during the explosion, as measured in the observer's reference frame?


Homework Equations


KE=1/2mv^2


The Attempt at a Solution



Since I have two masses, I don't know where to start on this problem. Any suggestions?
 
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Eventually the kinetic energy formula will come into play here, but during the explosion energy is NOT conserved, since it tells us the explosion adds energy. But can you tell me what is conserved in the explosion?
 
G01 said:
Eventually the kinetic energy formula will come into play here, but during the explosion energy is NOT conserved, since it tells us the explosion adds energy. But can you tell me what is conserved in the explosion?

Mass is conserved in this explosion but it's in two different forms.
 
Anything else?
 
G01 said:
Anything else?

Momentum?
 
shell4987 said:
Momentum?

Yup!:smile:

Now using momentum, can you find find the final energy of both masses?

If you can, then it is just a matter of finding the difference between the initial and final energy.
 
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