Differentiating acceleration using constant of motion

In summary, in order to find the acceleration in a changing gravitational field, we need to use the equations of motion and the force equation for a changing gravitational constant. This can be done by using the chain rule and substituting in the appropriate expressions for velocity and acceleration. However, it is important to note that this is a simplified model and further research is needed to accurately model this scenario.
  • #1
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Let's say we have an object falling through an accelerated field from r to s. I would say a gravitational field, as it is by the same process as gravity, but I will be applying a different constant of motion within the field.

If the constant of motion is something like (1 - b / r) = (1 - (v_r/c)^2), or (1 - b / r) / (1 - (v_r/c)^2) = K (constant for all r), where b is also constant, then the acceleration in terms of r can be found with

b / r = (v_r/c)^2, b / s = (v_s/c)^2

a = d(v^2) / (2 dr)

a = (v_s^2 - v_r^2) / (2 dr), where r - s = dr

a = c^2 (b / s - b / r) / (2 (r - s))

a = c^2 b (r - s) / (2 r s (r - s))

a = c^2 b / (2 r^2)

But what I want to know is how we would find the acceleration similarly to the above example with a constant of motion within an accelerated field of (1 - b / r) = (1 - v_r / c) / (1 + v_r / c) instead?
 
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  • #2


I would first clarify the terminology being used in this scenario. In physics, an accelerated field typically refers to a field where objects experience a force that causes them to accelerate. In this case, it seems that the term "accelerated field" is being used to describe a field with a changing gravitational constant.

In order to find the acceleration in this scenario, we would need to use the equations of motion in a changing gravitational field. This can be done by using the equation:

F = m (dv/dt) = m (d^2r/dt^2)

where F is the force, m is the mass of the object, v is the velocity, and r is the position.

In this case, the force experienced by the object would be given by:

F = G (1 - b/r)^2 m_1 m_2 / r^2

where G is the gravitational constant, b is the constant in the changing gravitational field, and m_1 and m_2 are the masses of the object and the source of the gravitational field, respectively.

Using the equation F = m (d^2r/dt^2), we can then solve for the acceleration:

a = (d^2r/dt^2) = G (1 - b/r)^2 m_2 / r^2

We can then use the chain rule to express this acceleration in terms of r:

a = (dr/dt) (d^2r/dr^2) = v (dv/dr)

Finally, we can substitute in the expression for v (dv/dr) to get the acceleration in terms of r:

a = (d/dr) (v^2) = (d/dr) [(c^2 (1 - b/r)^2) / (1 - v_r/c)^2]

This expression can then be simplified and solved for the acceleration in terms of r. However, it is important to note that this is a simplified model and may not accurately reflect the true behavior of objects in a changing gravitational field. Further research and experimentation would be necessary to fully understand and accurately model this scenario.
 

What is acceleration?

Acceleration is the rate at which an object's velocity changes over time. It is measured in meters per second squared (m/s^2).

What is a constant of motion?

A constant of motion is a physical quantity that remains unchanged throughout a system's motion. This means that its value does not depend on time or position.

How is acceleration differentiated using a constant of motion?

By using the chain rule from calculus, we can differentiate acceleration by taking the derivative of the constant of motion with respect to time. This gives us the rate of change of acceleration over time.

What are some common constants of motion used in differentiating acceleration?

In classical mechanics, the most commonly used constants of motion are energy, momentum, and angular momentum. In special relativity, the speed of light is also considered a constant of motion.

Why is differentiating acceleration using a constant of motion useful?

By using a constant of motion, we can simplify the process of finding acceleration and its changes over time. It also allows us to better understand the underlying physical principles at play in a system's motion.

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