circular motion Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is uniform circular motion?

A

Uniform circular motion is motion along a circular path in which there is no change in speed, only a change in direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the nature of speed in uniform circular motion?

A

constant speed tangent to path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the nature of the force in uniform circular motion?

A

It is a constant force that acts towards the centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is needed to change direction in circular motion?

A

centripetal force is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

if there was a ball moving in circular motion how would it move?

A

Ball moves tangent to path, NOT outward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens if centripetal force is removed?

A

When central force is removed, ball continues in straight line.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is continuously changing in circular motion if the speed of object is kept constant?

A

speed of the object is constant, it is continuously changing its direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the name given to acceleration in circular motion?

A

centripetal acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe centripetal acceleration

A

acceleration that acts towards the centre of the circular path and is perpendicular to the velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is happening to velocity in circular motion?

A

velocity is changing because direction is changing therefore causing an acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the centripetal acceleration caused by ?

A

caused by a centripetal force that also acts perpendicular to the direction of motion - newtons second law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

equation for linear speed

A

distance/time m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

equation for angular speed

A

angle/time rad/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

linear speed in terms of T (time period)

A

(2pir)/T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

angular speed in terms of T

A

2pi/T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is angular displacement

A

the change in angle, in radians of a body as it rotates around a circle

17
Q

angular displacement equation

A

ratio of distance travelled around the circle/ radius of circle

18
Q

how to convert degrees to radians

A

ø x π/180 = radians

19
Q

how to convert from radians to degrees

A

ø rad x 180/π = degrees

20
Q

what is angular speed?

A

the rate of change in angular disaplcement with respect to time

scalar quantity measured in radians per second

21
Q

equation
for angular speed?

A

change in angular displacement/time

22
Q

other equation for angular speed using 2pi as a complete cycle

A

v/r = 2pi f = 2pi/T

23
Q

what does the equation of angular velocity tell us?

A
  • the greater the rotation angle ø in a given amount of time, the greater the angular velocity w
  • an object rotating further from the centre of circle (larger radius) moved with smaller angular velocity (smaller w)
24
Q

definition of centripetal acceleration?

A

acceleration of an object towards centre of circle when an object in motion is rotating around a circle at a constant speed

25
Q

equation for centripetal acceleration

A

a = v squared/ r

26
Q

other equations for acceleration

A

a = rw squared

a = vw

27
Q

why do objects have a centripetal force?

A

an object moving in a circle is not in equilibrium, it has resultant force - centripetal force

28
Q

definition of centripetal force

A

the resultant force towards centre of circle requir to keep a body in uniform circular motion, not is always directed towards the centre of the body rotation

29
Q

is centripetal force a separate force of its own?

A

no it can be any type of force depending on the situation

30
Q

what would be the centripetal force if a cat is travelling around a roundabout?

A

friction between car tyres and the road

31
Q

what would the centripetal force if a ball is attached to a rope moving in a circle

A

tension in the rope

32
Q

what is the centripetal force if the earth Is orbiting the sun

A

gravitational force

33
Q

what happens at the top of a circle?

A

at the top of a circle the weight of the object is directly contributing to the centripetal force because it is acting directly towards the centre

this means that the inwards force such as for a ball being spun on a string is provided by the string - which is at minimum

34
Q

what happens at the sides of the circle?

A

the weight of the object acts perpendicular to the direction of centripetal force - meaning it makes no contribution and the force is provided externally

35
Q

what happens at the bottom of a circle?

A

the weight of the object is acting opposite to the direction of the centripetal force

inwards face of string must overcome the weight and provide the required centripetal force - meaning its at maximum

36
Q

what equation can you use to find T if you are given speed and radius

A

V =( 2pir )/ T

37
Q

how to find number of rotations in one minute?

A

angular speed x 60

38
Q

how do you find angle when given a time and angular speed

A

angular speed x time period given

39
Q
A