Lecture 20 - Torque and Motion Flashcards
1
Q
what is angular velocity?
A
- rate at which the angle changes with respect to time
- omega (w)
2
Q
what is the right-hand rule?
A
- determines angular velocity vector direction
3
Q
how do you calculate instantaneous angular velocity?
A
- w = d theta /d time
4
Q
how do you calculate instantaneous angular acceleration?
A
- dw / dt
5
Q
what is rotational inertia?
A
- I = mr^2
6
Q
how does mass increase affect rotational inertia?
A
- rotational inertia is doubled if mass is doubled
7
Q
how does radius increase affect rotational inertia?
A
- rotational inertia is increased when radius is increased - if mass radius is doubled, inertia is doubled^2
8
Q
what is the radius of gyration?
A
- k
- calculate inertia with I = mk^2
- special radius (for non-cylinders) (given to us)
9
Q
how are torque, angular acceleration and inertia changes related?
A
- torque increases with acceleration if inertia stays the same
- as inertia increases, acceleration decreases, if torque stays the same
- as torque increases, inertia increases, if acceleration stays the same
