Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you...
-
Upload
daniel-norman -
Category
Documents
-
view
237 -
download
0
Transcript of Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you...
![Page 1: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/1.jpg)
Chapter 11 Rotational Mechanics
![Page 2: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/2.jpg)
Torque
If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque.
Torque = force x lever arm distance
Example: 80 N
3 m
(80 N) x (3 m) = 240 N*m
![Page 3: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/3.jpg)
Lever Arm
The lever arm distance is the distance from the fulcrum to a point perpendicular to the applied force.
![Page 4: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/4.jpg)
Examples of Lever Arms
Find the lever arm in the following examples:
![Page 5: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/5.jpg)
Torque = force x lever arm distance
• Balancing Torques
Larger kid sits closer to fulcrum to balance torque
![Page 6: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/6.jpg)
![Page 7: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/7.jpg)
Inertia
• For objects at rest or in motion, they will tend to stay at rest or in motion unless acted on by an outside force
• Inertia is the tendency of an object to resist a change in its motion
• Inertia is dependent upon mass.
![Page 8: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/8.jpg)
Rotational Inertia
• The same is true for rotating objects:
• Rotational Inertia – tendency of an object to resist a change in rotation
![Page 9: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/9.jpg)
Moment of Inertia: The resistance of an object to changes in its rotational motion
Moment of intertia = (mass)(radius)2
I = mr2
![Page 10: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/10.jpg)
![Page 11: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/11.jpg)
Angular Momentum• Just as an object moving in a straight path has linear momentum, a rotating object has angular momentum.
• angular momentum = rotational inertia x rotational velocity
Angular momentum = I x ω
Angular Momentum: The measure of how difficult it is to stop a rotating object
Angular Momentum = (mass)(velocity)(radius)
L = mvr
![Page 12: Chapter 11 Rotational Mechanics. Torque If you want to make an object move, apply a force. If you want to make an object rotate, apply a torque. Torque.](https://reader036.fdocuments.us/reader036/viewer/2022062300/56649d215503460f949f5ec6/html5/thumbnails/12.jpg)
Law of Conservation of Angular Momentum:
If no unbalanced external torque acts on a rotating system, the angular momentum of that system is constant.