What Torque is Needed to Rotate a Solid Bored Ball?

AI Thread Summary
To calculate the torque needed to rotate a solid bored ball, the moment of inertia must first be determined using the formula I=1/2 m (r_i^2 + r_0^2), where r_i and r_0 are the inner and outer radial distances. The relationship between torque (T), moment of inertia (I), and angular acceleration (α) is expressed as T=Iα. There is uncertainty regarding whether to include the caps at the top and bottom of the ball in the moment of inertia calculation. If included, the moment of inertia of these caps must be calculated and added to that of the hollow cylinder. Understanding and applying these equations is essential for accurate torque calculation.
sushilshinge
Messages
3
Reaction score
0
I want to calculate the torque required to rotate a ball.
1. Ball is solid having mass M kg.
2. Ball is bored through about its axis.
3. Ball is rotating about the axis XX

Please see attached file.
 

Attachments

Last edited:
Physics news on Phys.org
You must find the moment of inertia of a hollow cylinder which is,
I=1/2 m ( r_i^2 + r_0^2)
r_i and the r_0 are radial distances from centre.

Than the relationship between torque, moment of intertia and angular acceleration, which is,
T=I \alpha

Now looking at the picture I am not sure if ur including those caps on the top and bottom. In which case you must find their moment of intertia and add it to the cylinder
 
Right side view is a section of a ball. The hatching part is a solid part of ball.When you will cut the ball in left view in middle then by looking left side it will look like in right view.
 
Not sure I completely understand what your saying. Are the equations what you are after? Just find the moment of inertia of the top and bottom parts, if indeed I am understanding you correctly
 

Thread '1:1 versus 2:1 Mechanical Advantage debate'

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...
View full post »

Thread 'Newton's first law?'

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?
View full post »
Thread 'Beam on an inclined plane'

Thread 'Beam on an inclined plane'

Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
View full post »

Similar threads

Ball hits a pivoting rod, what torque changes the angular momentum of the ball?
Replies
14
Views
2K
B The physics of flywheel launchers (like tennis ball shooters)
2
Replies
60
Views
4K
Why Doesn't the Ball Rotate When Hit by a Pivoting Rod?
Replies
30
Views
3K
I Writing an equation for torque around an arbitrary point on a body
Replies
6
Views
817
B Question about the definition of Torque Equilibrium
Replies
14
Views
731
B Impulse and distance from the axis of rotation
Replies
9
Views
2K
A Order of rotations due to torque in 3DOF in simulations
Replies
2
Views
1K
I What is the Purpose of Torque?
Replies
7
Views
2K
B Understanding Physics for Coding Collision of 2 Balls
Replies
14
Views
3K
I Torque required from powered roller to rotate cylinder
Replies
19
Views
2K

Hot Threads

Recent Insights

Back
Top