# Thread: Car physics question-been on my mind for several days!

1. Hi guys,
I just can't get this out of my head. I've tried looking for an answer but I'm not totally clear.

Okay, so lets say you have a car going real fast in a straight line and then you turn the car. The weight (or I guess theoretical mass or something?) shifts to the outside of the car.

Now I get that when the car is moving forward it has that inertia and when you turn, the inertia still wants to go in that straight line but you've turned so the vehicle has to cope by dipping down to that outside side.

My question is, how do you explain this using Einstein's ideas? Is the inertia turning into theoretical mass and that's why the car weights down on the outside? Also, what exactly is happening to space-time (if its being effected at all)?

If somebody could explain this to me as Einstein would, it would make me the happiest guy in the world.

Thanks.

2.

3. It has nothing to do with Einsteins ideas. The effect you see is the shocks compressing on one end, and decompressing on the other in order to allow for better banking. It shifts the inertia slightly downwards, pushing the energy into the earth rather than in the direction that you no longer want to go towards. This also increases the friction between the tires and the ground while turning which prevents sliding.

4. Â*
Einstein's theories do not apply. Not at all. This situation was solved back in the days of Isaac Newton (although it could only be applied to horse-drawn carriages).

There is a torque. The road is pushing the tires in the direction of the turn. The car's center of mass is above the point of applied force, so the car's body turns (leans) away from the direction of the force.

If you tried to apply Einstein's equations they would simply reduce to Newton's mechanics.

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5. Ah alright. Thanks for the replies guys.

6. Originally Posted by SteveF
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If you tried to apply Einstein's equations they would simply reduce to Newton's mechanics.

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True, but I think the OP was asking how one would conceive of centrifugal force and rotating frames of reference, in relativistic terms.

It seems that rotating frames of reference have been a difficult problem for relativity ever since Newton's bucket experiment:

http://www-groups.dcs.st-and.ac.uk/~...on_bucket.html

Newtons observation of the effects of centrifugal force is what led Newton to believe there was an absolute space reference frame. This view was challenged by Mach, who thought that a spinning bucket of water in space should be equivalent to a bucket sitting still with all the matter in the universe spinning around it. According to the above article, general relativity can explain Newton's bucket without any preferred space-time reference frame. It's not a simple thng, though.

7. Okay I'm confused again. Really really confused.

The two rocks tied together by the rope, why would they spin (and the rope become taut)? If they are the only two objects in the universe and they both have mass, why wouldn't gravity pull them together? I mean if I put two little balls on a sheet they would roll towards not away from each other right? Even if they were tied together.

Also, what is this saying? That the water in the bucket becomes concave because of what exactly? The earth's gravity? Or spin?

If anybody could help me out that would be awesome.

Thank you.

8. Originally Posted by MatTron
Okay I'm confused again. Really really confused.

The two rocks tied together by the rope, why would they spin (and the rope become taut)? If they are the only two objects in the universe and they both have mass, why wouldn't gravity pull them together? I mean if I put two little balls on a sheet they would roll towards not away from each other right? Even if they were tied together.

Also, what is this saying? That the water in the bucket becomes concave because of what exactly? The earth's gravity? Or spin?

If anybody could help me out that would be awesome.

Thank you.
Well, if you tie a rock to a rope and spin it around your head, the line becomes taut, doesnt it? Even though the rock and your head are attracted to one another by gravity. So, two rocks spinning around a common center would keep a rope taut, on earth or in space. Also there are binary stars orbiting a common center of mass. They are kept apart by the spinning motion, despite gravity pulling them together.

Now, if the two rocks are the only two objects in the universe, that's a different story. How would you ever tell they were spinning without a background of the rest of the universe?

As far as the bucket is concerned, didn't you ever stir the water in a bucket around in a circle and create a vortex? The gravity pulls the water down, tending to make a flat surface, but the spin is tending to force the water toward the sides of the bucket. The result is a concave surface.

9. Ahhh okay what you just said makes alot of sense. Thank you for the reply.

10. Originally Posted by MatTron
Ahhh okay what you just said makes alot of sense. Thank you for the reply.

I will give you my rather different way of learning about matter and centrifuge force.

Look at a baseball bat. The fellow in most cases is swinging in a arc like pattern. Yet when the ball is repelled by the bat. It leaves the bats surface perpendicular to the bats length. If it connects perpendicular to the pitchers throw.

The arc before and after the apparent contact appears to have no effect. The same is true of something moving in a straight line. The velocity applied to the car was applied in a straight line. The car is transformed into a diode so it can move through the ether or ambient radiation in a straight line only. Ambient radiation is a high velocity particle stream. That flows in all directions through everything. It is made up of the only subatomic particle in the universe, the electron.

In order to alter the car, or better put the moving diodes path. You have to alter the diodes angle. It requires repulsion in another direction to be applied. We often and commonly call this energy. However there really is no such thing. Just time and velocity and repulsion.

The force is caused by fighting the diodes natural straight path through ambient radiation.

You can actually use these forces from inside a sealed container to move the container. There were successful tests and funding was ended.

A recoiling barrel on a gun, creates this effect to maintain a super high level of accuracy. It does not allow the gun to pull up while the round is in the chamber if it is constructed correctly.
The movement of the heavy barrel keeps the gun as it was before it was fired. It requires force to change its direction from a straight path.

Sincerely,

William McCormick

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