Central Force problems using radial motion equation

In summary, the conversation discusses a satellite in a circular orbit above the Earth's surface and how its orbit changes when booster rockets are fired to double its speed without changing its direction. The equations for the satellite's total energy and potential energy are given, and it is noted that after the boost, the satellite's total energy becomes positive which could result in an escape from Earth's orbit. The concept of orbit is further defined as a hyperbolic path, and a resource for obtaining equations for this path is mentioned.
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Homework Statement


a satellite is in a circular orbit a distance $h$ above the surface of the Earth with speed $v_0$, booster rockets are fired which double the speed of the satellite without changing the direction. Find the subsequent orbit.

Homework Equations


The Attempt at a Solution


Before the rocket boost, If we use the radial motion equation we can find the total energy of the system, that is given by:

$$E = \frac{1}{2}\dot{r}^2 + V + L^2/2r^2 = \frac{v_0^2}{2} - \frac{\gamma}{R_e + h}$$

Where I have assumed the presence of an attractive inverse square law.
and $L = rv_0$.

How can I continue from here? surely when the velocity increases, it isn't going to continue in a circular orbit.

After the boost, we have $$\frac{1}{2}\dot{r}^2 + V + L^2/2r^2 = \frac{1}{2}\dot{r}^2 - \frac{L^2}{2r^2} - \frac{\gamma}{r} = E $$we can write

$$\frac{1}{2}4v_0^2 - \frac{L^2}{2r^2} - \frac{\gamma}{r} = E $$

then equating

I obtain

$$\frac{L^2}{2r^2} + \frac{\gamma}{r} = \frac{\gamma}{R_e + h} + \frac{3}{2v_0^2}$$

I don't see how the solutions to the above equation describe the orbit
 
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Won't it escape the Earth? Since before the boost we have ##\frac{v^2}{r}=\frac{GM}{r^2}## where ##M## is the Earth's mass, we have ##v=\sqrt{\frac{GM}{r}}##, the gravitational potential energy is ##-\frac{GMm}{r}=-mv^2## and the total potential energy is ##-\frac{1}{2}mv^2##. If the speed is doubled, the KE goes to ##2mv^2## and the total energy goes to ##mv^2##, which is positive, implying escape on a hyperbolic trajectory (ignoring the fact that it will be captured by the Sun).

So I guess by orbit, they mean the hyperbolic path it will follow. The equations for that path should be readily obtainable from a page on orbital trajectories such as this.
 
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1. What is the central force problem in physics?

The central force problem in physics involves the study of the motion of a particle under the influence of a force that is directed towards a fixed point, known as the center of force. This force is known as a central force and can be expressed using the radial motion equation.

2. What is the radial motion equation?

The radial motion equation is a mathematical expression that describes the motion of a particle under the influence of a central force. It is given by the equation F(r) = m(d^2r/dt^2), where F(r) is the central force, m is the mass of the particle, r is the distance from the center of force, and t is time.

3. What is the relationship between central force and radial acceleration?

The radial motion equation shows that the central force is directly proportional to the radial acceleration of the particle. This means that as the central force increases, the radial acceleration also increases, and vice versa.

4. How is the motion of a particle affected by changes in the central force?

Changes in the central force can affect the motion of a particle in several ways. If the central force increases, the particle will experience a greater radial acceleration and will move faster towards the center of force. On the other hand, if the central force decreases, the particle will experience a smaller radial acceleration and will move slower towards the center of force.

5. What are some real-life applications of central force problems using radial motion equation?

The radial motion equation is used in various fields of science and engineering, such as astronomy, astrophysics, and aerospace engineering. It is used to study the motion of planets and satellites in orbit around a central body, as well as the motion of particles in nuclear physics and the behavior of particles in particle accelerators.

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