Thread: Slowing down of an object

A spinning wheel is pushed.

I wonder if it might perhaps slow down its spinning?

Like because, non-spinning mass-energy is perhaps added to the wheel?

For a change, we have a moving wheel, not spinning, and we try to make it spin.

Let's make the speed of the wheel 99 % of c (speed of light)

How fast can we make the wheel spin?

Note that we are not moving with the wheel. Note also that nothing is forcing the speed to
stay 99 % of c


(I very humbly suggest that adding spin slows down the linear motion )

Originally Posted by jartsa

A spinning wheel is pushed.

I wonder if it might perhaps slow down its spinning?

Like because, non-spinning mass-energy is perhaps added to the wheel?

nope

Is there no end to your lack of understanding of elementary physics ?

It all depends on how the wheel is pushed and what torques are applied in the process.

Originally Posted by DrRocket

Originally Posted by jartsa

A spinning wheel is pushed.

I wonder if it might perhaps slow down its spinning?

Like because, non-spinning mass-energy is perhaps added to the wheel?

nope

What does the "nope" mean here?
Does it mean: "Spinning wheel does not slow down when non-spinning mass-energy is added to it?"

We have a wheel that is spinning so that some point in it is rotating at speed 0.5 c.

How much linear speed can we give this wheel?

Answer is perhaps "1.0 c is the limit"

If we have given the wheel linear speed 0,9 c , and the rotating speed is still 0,5 c,
then a point on the wheel is moving faster than the speed of light. So this maybe is
impossible.

So does the correct procedure to accelerate the wheel to near c speeds include stopping
the wheel?

I mean, does just plain very big catapult work?

What you are asking for is an infinitely rigid wheel, and as such it is impossible. You also already assume that the wheel has been accelerated to a rotation that involves a rotational speed at an assumed radius. This wouldn't work, because a real wheel would break apart because of shear forces along the radius.

Originally Posted by Dishmaster

What you are asking for is an infinitely rigid wheel, and as such it is impossible. You also already assume that the wheel has been accelerated to a rotation that involves a rotational speed at an assumed radius. This wouldn't work, because a real wheel would break apart because of shear forces along the radius.

Then tell me what kind of spinning wheel we can have. This seems like pseudo-science what
you say.



Question:

Bikecycle wheel spins at speed 1 m/s

Is it possible to accelerate this wheel to speed
0.999999999999999999999999999999999999999999999999 99999999999999999 c ,
using a catapult?