Circular motion

Question 1

is velocity vector or scalar

Answer 1

vector

Question 2

is acceleration vector or scalar

Answer 2

vector

Question 3

describe the reason why centripetal acceleration exists AND what it is

Answer 3

• An object in uniform circular motion has a constant linear speed
• However, it is continuously changing direction. Since - velocity is the speed in a given direction, it, therefore, has a constantly changing velocity
• The object therefore must be accelerating
• This is because acceleration is defined as the rate of change of velocity
• This acceleration is called the centripetal acceleration and is perpendicular to the direction of the linear speed

Question 4

what does centripetal mean

Answer 4

acts towards the centre of a circular path

Question 5

draw a diagram of the different forces acting on an object in circular motion

Answer 5

Question 6

angular displacement def

Answer 6

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

Question 7

What is angular displacement the ratio of

Answer 7

Question 8

radian def

Answer 8

The angle subtended at the centre of a circle by an arc equal in length to the radius of the circle

Question 9

what do the components of the angular displacement equation mean

Answer 9

Question 10

what is the angle in radians of 360 degrees

Answer 10

2 pi

Question 11

what is the equation to convert from degrees to radians

Answer 11

Question 12

angular speed def

Answer 12

The rate of change in angular displacement with respect to time

Question 13

Why is an object moving in a circle accelerating?

Answer 13

• Any object travelling in a uniform circular motion at the same speed travels with a constantly changing velocity
• This is because it is constantly changing direction, and is therefore accelerating

Question 14

What do the components of the angular speed equation mean?

Answer 14

Question 15

What does the angular speed equation say about circular motion?

Answer 15

• The greater the rotation angle θ in a given amount of time, the greater the angular velocity ⍵
• An object rotating further from the centre of the circle (larger r) moves with a smaller angular velocity (smaller ⍵)

Question 16

centripetal acceleration def

Answer 16

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

Question 17

Describe the two equations which combine to form the centripetal acceleration equation

Answer 17

Question 18

What are the components of the equation, a=vw

Answer 18

a = centripetal acceleration (m s−2)
v = linear speed (m s−1)
⍵ = angular speed (rad s−1)

Question 19

centripetal force def

Answer 19

The resultant force towards the centre of the circle required to keep a body in uniform circular motion. It is always directed towards the centre of the body’s rotation.

Question 20

What do the components of the centripetal force equation mean?

Answer 20

Question 21

does the centripetal force act in the same direction an centripetal acceleration?

Answer 21

yes

Question 22

what are 3 examples of centripetal forces

Answer 22

Question 24

For a ball on a string moving in circular motion, describe newton’s three laws acting on it, as well as an explanation why it won’t be moving horizontally

Answer 24

Question 25

Answer 25