Need help with gravitation conservation of energy problem

AI Thread Summary
The discussion addresses a gravitation conservation of energy problem involving a hypothetical planet named Zero. A 17 kg space probe is launched with an initial kinetic energy of 5.0E7 J, and the calculations show that its kinetic energy at a distance of 4.0E6 m from the center of Zero is 3.11E7 J. The potential energy is calculated using the formula U=-(GmM/r), leading to the total energy equation E=K initial + U initial. Additionally, to achieve a maximum distance of 8.0E6 m, the required initial kinetic energy for the probe is determined. The solution confirms the calculations are correct and provides clarity on the energy conservation principles involved.
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[SOLVED] need help with gravitation conservation of energy problem

Homework Statement


Zero, a hypothetical planet, has a mass of 2.0E23 kg, a radius of 3.0E6 m, and no atmosphere. A 17 kg space probe is to be launched vertically from its surface.
(a) If the probe is launched with an initial kinetic energy of 5.0E7 J, what will be its kinetic energy when it is 4.0E6 m from the center of Zero?

(b) If the probe is to achieve a maximum distance of 8.0E6 m from the center of Zero, with what initial kinetic energy must it be launched from the surface of Zero?


Homework Equations


E=K+U
U=-(GmM/r)

The Attempt at a Solution


E=K initial + U initial
E=5.0E7+(-(6.67E-11)(17)(2.0E23))/3.0E6=-2.56E7
E-U final=K final
-2.56E7--5.67E7=3.11E7J
is this correct?
 
Last edited:
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Yes. That's right.
 
thanks
 
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