Distribution of mass and angular momentum

AI Thread Summary
The distribution of mass in two cylinders affects their angular momentum when rolling down an incline. Cylinder one, with mass distributed around an outer radius, will have a greater moment of inertia compared to cylinder two, which has mass concentrated near the inner radius. Consequently, cylinder two will have a higher angular momentum for the same rotation rate due to its lower moment of inertia. To solve for angular momentum (L), the actual mass distribution must be known, as it directly influences the moment of inertia calculation. Understanding these principles is crucial for accurately determining the angular momentum of each cylinder.
eshali
Messages
2
Reaction score
0
If I had two cylinders of equal weight and size, but cylinder one had the weight distributed around an outer radius and cylinder two had it distributed around an inner one, would it change their angular momentum going down an incline? Would they be equal, or would cylinder two have greater momentum? And how would I reflect this when solving for L?
 
Physics news on Phys.org
The moment of inertia of a body is calculated by integrating dm r2, where dm is an element of mass and r is its distance from the axis of rotation. Thus, when mass is close to the axis (your cylinder two), the MI is less, so for a given rotation rate the angular momentum is less.
To calculate it you will need to know the actual mass distribution.
 
Thanks!

For the problem itself, I will have numbers for the mass, which is distributed equally around the center of the cylinder, so will be able to calculate the actual momentum.
 
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...
Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
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?
Back
Top