Angular velocity of sphere and two points

In summary, the problem involves a uniform sphere of mass m and radius R rotating around a vertical axis with angular speed \omega. Two particles of mass m/2 are added to the sphere at diametrically opposite points at an angle \Theta from the vertical, causing the moment of inertia to change. The resulting question is what angle the resulting angular velocity, \vec{\omega}, makes with the vertical. Conservation of angular momentum can be used to solve this problem.
  • #1
KaiserBrandon
54
0

Homework Statement


A uniform sphere of mass m and radius R rotates around the vertical axis with angular speed [tex]\omega[/tex]. Two particles of mass m/2 are brought close to the sphere at diametrically opposite points, at an angle [tex]\Theta[/tex] from the vertical. The masses, which are initially essentially at rest, abruptly stick to the sphere. What angle does the resulting [tex]\vec{\omega}[/tex], make with the vertical?


Homework Equations


so the moment of inertia of the sphere by itself is [tex]I=\frac{2}{5}mR^{2}[/tex]



The Attempt at a Solution


I don't really know how to start this question off, or what method I would use. There is a changing moment of inertia, so would I use conservation of angular momentum to find the resulting angular velocity?
 
Physics news on Phys.org
  • #2
Yes, that's exactly right. Why not try and solve it and show us if you get stuck at any point along the way?

As a general note, we won't do your homework for you here, you should show your own attempt at the solution in order for us to help you the best we can.
 

1. What is angular velocity?

Angular velocity is a measure of the rate at which an object rotates around a fixed point. It is represented by the Greek letter omega (ω) and is measured in radians per second or degrees per second.

2. How is angular velocity different from linear velocity?

Angular velocity is a rotational motion, while linear velocity is a straight-line motion. Angular velocity measures the rotational speed of an object, while linear velocity measures the speed at which an object is moving in a straight line.

3. How is the angular velocity of a sphere calculated?

The angular velocity of a sphere is calculated by dividing the change in its angular displacement (θ) by the change in time (t). It is represented by the equation ω = Δθ/Δt and is measured in radians per second.

4. Can the angular velocity of a sphere change?

Yes, the angular velocity of a sphere can change if there is a change in its rotational speed or if there is a change in the direction of its rotation. This change can be caused by external forces such as torque or friction.

5. How is the angular velocity of two points on a rotating object related?

The angular velocity of two points on a rotating object is related by the distance between the points and the angular displacement of the object. The farther apart the points are, the greater the difference in their angular velocities will be. However, if the object rotates at a constant rate, the ratio of their angular velocities will remain the same.

Similar threads

  • Introductory Physics Homework Help
10
Replies
335
Views
8K
  • Introductory Physics Homework Help
Replies
32
Views
1K
  • Introductory Physics Homework Help
Replies
30
Views
2K
  • Introductory Physics Homework Help
3
Replies
97
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
179
  • Introductory Physics Homework Help
Replies
17
Views
375
  • Introductory Physics Homework Help
Replies
10
Views
886
  • Introductory Physics Homework Help
Replies
3
Views
770
  • Introductory Physics Homework Help
2
Replies
40
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
974
Back
Top