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- Homework Statement
- A person with a mass of 50kg falls onto a trampoline with a downward speed of 4.89 m/s. Due to the trampoline, the person experiences a net upward force of 887 N for a time of 0.578 s.

The person leaves the trampoline with a speed of ___ in the upward direction.

- Relevant Equations
- P0+J=Pf

KE0+PE0+Wnc=KEf+PEf

I was able to calculate the correct answer (given by a solution sheet), V=5.364 m/s, using the momentum impulse equation, P0+J=Pf. If this value is correct, however, I don't understand how energy is being conserved. The speed increases after the person bounces off the trampoline while the mass remains constant. Thus there is a net increase in kinetic energy. The only answer that I can think of is that the problem statement treated the trampoline as applying a force to the person that was not commensurate with the action of a spring, in other words, as doing non-conservative work. I just want to make sure I am not missing something here conceptually. Thanks, and sorry if I made any mistakes with this post.

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