Centrifugal force in space Motor with axle and wheight

AI Thread Summary
Centrifugal and centripetal forces in space are often discussed in the context of spinning space stations, but the mechanics of a motor with an axle and mass raise questions about motion in a frictionless environment. When the motor is activated, the system will spin around its center of mass rather than wobble, and any movement by astronauts within a spacecraft can affect its balance, albeit minimally. The Hubble Space Telescope employs reaction wheels to manage its orientation, illustrating practical applications of these principles. Understanding the dynamics of connected masses is crucial, as they will rotate around their center of mass, adhering to the laws of physics. The discussion emphasizes that internal actions cannot result in translation without violating conservation of momentum.
ZelfZA
Messages
4
Reaction score
1
HI.

I've read a lot of posts on centrifugal and centripetal force in space. But they mostly refer to the spinning space stations.

I would like to know what happens when you take a motor with an axle and a mass on the end on of the axle, and you start the motor up.. I understand the whole law of "every action has a opposite equal reaction".
But does this mean the motor will follow the mass in a small circle or will the whole thing just "hang" there wobbling about?

Does anyone know if it has been tested in space?

To add to my question...

If a person in a "spinning" spaceship touches the side and gets "caught" in the "gravity".. Does it make the ship off balance?

I hope you get my question - understand it I mean.. It's bugging me.
 
Physics news on Phys.org
Welcome to PF!

The Hubble Space Telescope uses exactly that concept to aim it. The motor spins the wheel one way and that makes the Hubble spin the other way:
http://en.wikipedia.org/wiki/Reaction_wheel

And yes, astronauts moving around in a spacecraft will affect its attitude. Fortunately, the astronauts are a lot lighter than the spacecraft so the effect is small.
 
Thanks for the speedy reply and the link to the Reaction wheel.

I assume the speed of the wheel and the mass of it will be determined by the mass of the ship.

All of this is relevant to my experiment of the last 4 years.
A theory similar to that of Nikola Tesla's Flying machine.
But I would Like to see my Experiment Succeed or Fail..
Before I make any claims.
 
I think you need to go back and understand something simpler.

Two masses, m1 and m2, are connected via a rigid rod with negligible mass. So you then set it to spin in your "space", i.e. no friction, no gravity.

They will both spin about the center of mass of the system! The location of the center of mass depends on the mass m1 and m2, and how far apart they are. If m1=m2, then the COM will be right in the middle of the two. For the Earth-Moon system, it is close to the center of the Earth since m_Earth>>m_Moon.

You need to look at your "motor-axel-mass" with this level of understanding.

Zz.
 
ZelfZA said:
Thanks for the speedy reply and the link to the Reaction wheel.
You're welcome!
I assume the speed of the wheel and the mass of it will be determined by the mass of the ship.
Correct.

Also worth noting that despite your title this doesn't have anything to do with centrifugal force.
All of this is relevant to my experiment of the last 4 years.
A theory similar to that of Nikola Tesla's Flying machine.
But I would Like to see my Experiment Succeed or Fail..
Before I make any claims.
Uh oh. That can't lead anywhere good. Note that:
1. What we are discussing can only cause rotation, not translation.
2. Internal action causing translation would violate conservation of momentum.
3. We don't deal in things that violate the laws of physics here.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top