# 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