Angular Kinetics Flashcards
In which situation is no torque applied
If angular velocity does not change and the system does not accelerate
For every torque, there is a torque of _______ magnitude directed in the _______ direction
equal; opposite
Define inertia
resistance of a system to having its state of motion changed by application of a force
How is inertia different in linear vs angular kinetics
linear = mass
angular = moment of inertia
What 3 things does moment of inertia depend on
- mass
- mass distribution
- axis of rotation
Define the radius of gyration
the distance that represents how far the mass of a rigid body would be from an axis of rotation if its mass were concentrated at one point
what is angular acceleration directly proportional to?
Net torque
what is angular acceleration inversely proportional to?
the rotational inertia of the segment being accelerated
What is the most efficient way to move the human body?
To maximize acceleration while minimizing torque requirements (decreasing moment of inertia)
If you increase the moment of inertia for the same torque, what happens to the angular acceleration?
It increases
Define momentum
A system’s quantity of motion
What are the rules of conservation of angular momentum
There can be no change in momentum without an externally applied force
How can there be a change in velocity (acceleration) without a torque being applied
No force, no impulse, vf=vi
Can velocity change without changing momentum?
No torque, no change in angular momentum
How can moment of inertia be manipulated?
By modifying mass distribution
