Angular Momentum and Average Torque

In summary, the conversation discusses the conservation of angular momentum and the calculation of average torque. The initial angular momentum is equal to the final angular momentum and the average torque is found by dividing the change in angular momentum by the change in time. However, it is noted that the total angular momentum is conserved and the angular velocity changes from 0 to 26.03 in 7 seconds. The use of standard constant acceleration equations is suggested to find the average angular acceleration.
  • #1
mohabitar
140
0
gL16y.png


Refer to number 6. This is the one I'm stuck on. So angular momentum is conserved right, so initial angular momentum is equal to final angular momentum. Initial is 7.87 so final must be 7.87, right? And so average torque is just change in angular momentum / change in time, so 0/7=0. What am I doing wrong?
 
Physics news on Phys.org
  • #2
hi mohabitar! :smile:
mohabitar said:
… So angular momentum is conserved right, so initial angular momentum is equal to final angular momentum. Initial is 7.87 so final must be 7.87, right? And so average torque is just change in angular momentum / change in time, so 0/7=0.

no, total angular momentum is conserved, but the angular momentum of the rod isn't …

the angular velocity of the rod changes from 0 to 26.03 in 7 s …

so use one of the standard constant acceleration equations to find the (average) angular acceleration :wink:
 

1. What is angular momentum?

Angular momentum is a measure of an object's rotational motion. It is defined as the product of an object's moment of inertia and its angular velocity.

2. How is angular momentum different from linear momentum?

Linear momentum is a measure of an object's motion in a straight line, while angular momentum is a measure of an object's rotational motion. Linear momentum is calculated by multiplying an object's mass by its linear velocity, while angular momentum is calculated by multiplying an object's moment of inertia by its angular velocity.

3. What is torque?

Torque is a measure of the force that causes an object to rotate around an axis. It is calculated by multiplying the force applied to an object by the distance from the axis of rotation to the point where the force is applied.

4. How is torque related to angular momentum?

Torque and angular momentum are closely related, as torque is the rate of change of angular momentum. In other words, an object's angular momentum will change when a torque is applied to it.

5. What is average torque?

Average torque is the average amount of torque applied to an object over a given period of time. It is calculated by dividing the total torque applied by the duration of time over which it was applied.

Similar threads

  • Introductory Physics Homework Help
Replies
30
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
681
  • Introductory Physics Homework Help
Replies
4
Views
773
Replies
3
Views
665
  • Introductory Physics Homework Help
Replies
10
Views
886
  • Introductory Physics Homework Help
2
Replies
45
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
505
  • Introductory Physics Homework Help
10
Replies
335
Views
8K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
Back
Top