What has a higher total energy?

Please tell us what you find unclear.In summary, a satellite with a 40.0kg mass in a 177km orbit has a larger total energy than the same satellite in a 144km orbit. This is due to the fact that it takes more energy to move the satellite to infinity from a larger orbit, and the further out the satellite is, the easier it becomes to reach infinity. Friction is not considered in this scenario.
  • #1
jakeginobi

Homework Statement


Why does a satellite that has a 40.0kg mass in its 177km orbit has a total energy larger than its 144 km orbit?

Homework Equations


Ep = -GMm/r, Et = -GMm/2r

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
 
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  • #2
jakeginobi said:

Homework Statement


Why does a satellite that has a 40.0kg mass in its 177km orbit has a total energy larger than its 144 km orbit?

Homework Equations


Ep = -GMm/r, Et = -GMm/2r

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

You have a negative value for ##E_t##, which I assume is kinetic energy.
 
  • #3
PeroK said:
You have a negative value for ##E_t##, which I assume is kinetic energy.
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
@jakeginobi If you have the total energy, what's your question?
 
  • #5
jakeginobi said:
there's friction involved
Not in the problem statement, not in the relevant equations.
Together with PeroK, I wonder how we can best help you.
 

FAQ: What has a higher total energy?

What has a higher total energy?

The concept of total energy is a complex one and can be measured in different ways. Here are five frequently asked questions about what has a higher total energy:

1. Is a moving object's total energy always higher than a stationary object's?

Not necessarily. While a moving object does have kinetic energy, a stationary object can have potential energy due to its position or arrangement of particles. The total energy of an object depends on both its kinetic and potential energies.

2. Does a larger object always have a higher total energy?

Not always. While a larger object may have more particles and thus more potential energy, the total energy also depends on the speed and motion of those particles. A smaller object with high speed can have a higher total energy than a larger object with lower speeds.

3. Do chemical reactions always result in an increase in total energy?

No, it depends on the type of reaction. Exothermic reactions release energy, resulting in a decrease in total energy, while endothermic reactions absorb energy, resulting in an increase in total energy.

4. Can potential energy ever be higher than kinetic energy?

Yes, in certain situations. For example, a rollercoaster at the top of a hill has high potential energy but low kinetic energy, while at the bottom of the hill it has low potential energy but high kinetic energy.

5. How does temperature affect an object's total energy?

Temperature is directly related to an object's kinetic energy. As temperature increases, so does the average speed of particles, resulting in a higher total energy. However, temperature does not affect potential energy, which depends on an object's position or arrangement of particles.

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