Flashcards in Unit 1- Rotational motion Deck (24):

1

## What is the definition of inertia?

### The resistance to motion(Angular acceleration).

2

## Deriving displacement gives you?

### Velocity.

3

## Deriving Velocity gives you?

### Acceleration.

4

## Integrating acceleration gives you?

### Velocity.

5

## Integrating velocity gives you?

### Displacement.

6

## Can we change the equations of motion from linear physics and apply them to rotational problems?

### Yes, we just input the angular values for each.

7

## How can you work out W (Omega)?

### 2π/T (Period or time) , 2πf

8

## How can you work out angular displacement?

### 2π

9

## in 1 rev the distance travelled is?

### 2πR

10

## a machine rotates at 3000 rpm, whats the angular velocity?

### 3000x2π/60= 314.2 rads^-1

11

## how do you get linear to tangential velocity?

### v=W(omega)xR

12

## what is centripetal acceleration?

### if an object is travelling in a circle there is a force pulling it out of its natural linear motion and into a circular one, this force is an inward seeking force causing the object to have an inward acceleration.

13

## if a ball is swung horizontally whats the equation for centripetal force?

### Fcp= mv^2/r=T

14

## if a ball is swung vertically whats the equation for centripetal force?

###
TOP- Fcp=mv^2/r = T+W

Bottom- Fcp=mv^2/r = T-W

15

## If a car goes over a bridge whats the equation for Centripetal force? what happens to the reaction force when the car leaves the ground?

### Fcp=mv^2/r=W-R, the reaction force would be 0 if car lifts off the ground.

16

## what is a torque?

### Tangential force x Radius(Distance) from the axis of rotation, if the force is applied at and angle then the equation is multiplied by sin(Angle)

17

## is angular momentum always conserved in the absence of external forces?

### yes, however kinetic energy isn't always.

18

## whats can we say about the force between masses?

### They're always attractive.

19

## what is the moment of inertia?

### The measure of how difficult it is to change the motion of a rotating body.

20

## what is gravitational potential measured from?

### Gravitational potential is measured from infinity to 0

21

## what 2 equations derive the period for satellites?

### Mv^2/r = GM1M2/r^2 (knowing that: v=Wr and w=2π/T)

22

## whats the difference between special and general relativity?

### special = objects moving with a constant speed, general = objects which are accelerating.

23

## what is the equivalence principle?

### There is no way to distinguish the effect on an observer of being accelerated or being in a uniform gravitational field.

24