How Much Energy Is Required to Launch a Satellite into Orbit?

In summary, a satellite of mass 200 kg is launched into an orbit at 205 km above the surface of Earth with an orbital period of 5300 s and an orbital velocity of 7788 m/s. Using the kinetic energy equation, the minimum energy necessary to place the satellite in orbit is calculated to be 6.07 E 9 J, assuming no air friction. To find the potential energy, the total energy, and the kinetic and potential energy of the satellite sitting at the equator, calculations are done using the final kinetic and potential energies as well as the initial kinetic energy of the satellite when it is on the surface of the Earth. It is recommended to use the Earth's radius for the initial potential energy calculation.
  • #1
crr2010
2
0
1. Homework Statement

A satellite of mass 200 kg is launched from a site on Earth's equator into an orbit at 205 km above the surface of Earth. What is the minimum energy necessary to place the satellite in orbit, assuming no air friction? I also figured the orbital period to be 5300 s and the orbital velocity to be 7788 m/s

2. Homework Equations
P = -GMm/r
K = .5*m*v^2

3. The Attempt at a Solution
I plugged the numbers into the kinetic energy equation
.5*200 kg*(7788 m/s)^2
and got 6.07 E 9
 
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  • #2
What's the potential energy of the satellite in orbit?
What's the total energy of the satellite in orbit?
What's the kinetic and potential energy of the satellite sitting at the equator?
 
  • #3
final kinetic = 6.065 E 9 J
final potential = 1.211 E 10 J
final total energy = -6.049 E9 J

initial kinetic = 2.153 E 7 J (using Earth's rotational period of 463.9 s to find Earth's v)
now here's where I am not sure
for initial potential energy do you use the total radius or just the radius of the earth?
 
  • #4
crr2010 said:
final kinetic = 6.065 E 9 J
final potential = 1.211 E 10 J
final total energy = -6.049 E9 J

initial kinetic = 2.153 E 7 J (using Earth's rotational period of 463.9 s to find Earth's v)
now here's where I am not sure
for initial potential energy do you use the total radius or just the radius of the earth?

Since it is sitting on the surface of the Earth, doesn't it make sense to use the Earth's radius?
 

What is the definition of "Energy needed to orbit"?

The energy needed to orbit refers to the amount of energy required for an object to maintain a stable orbit around another object, such as a planet or a star.

How is the energy needed to orbit calculated?

The energy needed to orbit is calculated using the formula E = GmM/2r, where E is the energy, G is the gravitational constant, m is the mass of the orbiting object, M is the mass of the object being orbited, and r is the distance between the two objects.

Does the energy needed to orbit vary for different objects?

Yes, the energy needed to orbit can vary depending on the mass and distance of the objects involved. For example, the energy needed to orbit the Earth is different from the energy needed to orbit the Moon.

What factors affect the energy needed to orbit?

The main factors that affect the energy needed to orbit are the mass and distance of the objects involved. Other factors such as atmospheric drag and gravitational influences from other objects can also affect the energy needed to maintain an orbit.

Why is the concept of energy needed to orbit important?

The concept of energy needed to orbit is important because it helps scientists understand and predict the motion of objects in space. It also plays a crucial role in the design and operation of spacecraft and satellites, which rely on precise calculations of energy needed to maintain their orbits.

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