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## Homework Statement

Complete the chart for a 1kg rock and its trip through the earth's gravitational firled. The rock was powerfully launched straight up from the surface of the earth at 1x10^4 m/s.

Note: An object's kinetic energy must be a (+)-value; a negative value is impossible.

## Homework Equations

Eg = -GmM/r

Ek = GMm/2r

mEarth = 6*10^24 kg

Re = 6.4*10^6 m

## The Attempt at a Solution

Basically, we had to set distance as a variable, and see how the energies (Ek and Eg) would change.

The total energy is constant, and it is found to be -1.25*10^7 J

Ok If I solve for E for instance, 6 times the radius of the earth, I will get -1.04x10^7 J of Eg. However, when I try to solve for Ek:

Ek + Eg = ET

Ek = ET - Eg

Ek = (-) answer, since the Eg was smaller than the overall ET, which was found to be -1.25*10^7.

Is this still valid?

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