# What has a higher total energy?

1. Jan 16, 2017

### jakeginobi

1. The problem statement, all variables and given/known data
Why does a satellite that has a 40.0kg mass in its 177km orbit has a total energy larger than its 144 km orbit?

2. Relevant equations
Ep = -GMm/r, Et = -GMm/2r

3. The attempt at a solution
I figured from using the Et equation, the greater the radius the bigger the value, but I don't know how to explain it in terms of potential energy and kinetic energy. Also its path is a circular orbit and there's friction involved

2. Jan 16, 2017

### PeroK

You have a negative value for $E_t$, which I assume is kinetic energy.

3. Jan 16, 2017

### BvU

Total energy.

Basically: it takes energy to move the satellite to infinity. More energy than the kinetic energy (namely twice as much).

The further out you start, the easier it becomes ==> total energy is larger at 177 than at 144 km up.

4. Jan 16, 2017

### PeroK

@jakeginobi If you have the total energy, what's your question?

5. Jan 16, 2017

### BvU

Not in the problem statement, not in the relevant equations.