# Angular momentum and orbital angular momentum problems

1. Feb 4, 2005

### sebasalekhine7

1. A proton of mass rotates with an angular speed of 2*10^6 rad/s in a circle of radius 0.8m in a cyclotron. What is the orbital angular momentum of the proton?

2.An object's angular momentum changes by 10Kgm/s^2. What magnitude average torque acted on this object?

3. A pulsar which emits radio waves 642 times per second has a mass of 2*10^30 kg and has a radius of only 15km.
a) What is the linear speed of a point on the equator of this pulsar? Ignore relativistic effects.
b) If our sun, with mass 2*10^30 kg and radius 7*10^5 km had the same angular momentum as this pulsar, approximately what would its rotational period be?

BTW, how do I upload an avatar to my profile? I tried in the CP but I didn't find any option that would allow me to do so.

Last edited: Feb 4, 2005
2. Feb 4, 2005

### Gokul43201

Staff Emeritus
3. Feb 5, 2005

### sebasalekhine7

I understand what you mean by your post, but I have little to work with, since we are not having these topics in our physics class, this is independent study for the science league. Let's see, I have $$I=2/5MR^2$$ , I also have $$\omega=v/r$$

I think 3a is like this: Ok, I think I have 3a. it is rotating at $$(642rev/s)(2\pi rad/rev)(15000m)=V$$

Besides this, I have no idea as to what to do next.

Last edited: Feb 5, 2005
4. Feb 5, 2005

### sebasalekhine7

Ok, I think I've got question # 1. Is orbital angular momentum =angular velocity*radius^2 ?

Last edited: Feb 5, 2005