Question

Zero, a hypothetical planet, has a mass of 2.7 x 10^23 kg, a radius of 2.8 x 10^6 m, and no atmosphere. A 3.6 kg space probe is to be launched vertically from its surface. (b) If the probe is to achieve a maximum distance of 4.6 × 10^6 m from the center of Zero, with what initial kinetic energy must it be launched from the surface of Zero?

Answer 1

The kinetic energy when it reaches its final height must be 0. By conservation of energy, the energy it has at its final height is equal to the energy when it is launched.

Answer 2

Got it & Thanks! I was just messing up the (-) signs the whole time. Thanks.