Angular momentum and orbital angular momentum problems

AI Thread Summary
The discussion focuses on solving problems related to angular momentum and torque. A proton's orbital angular momentum is calculated using its mass, angular speed, and radius in a cyclotron setup. The average torque acting on an object is determined from a change in angular momentum. Additionally, calculations for a pulsar's linear speed and the rotational period of the sun, assuming equal angular momentum, are explored. Participants also seek guidance on uploading an avatar to their profile, indicating a mix of physics inquiry and forum navigation questions.
sebasalekhine7
Messages
23
Reaction score
0
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:
Physics news on Phys.org
https://www.physicsforums.com/showthread.php?t=28
 
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:
Ok, I think I've got question # 1. Is orbital angular momentum =angular velocity*radius^2 ?
 
Last edited:
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top