Circular motion Flashcards
is velocity vector or scalar
vector
is acceleration vector or scalar
vector
describe the reason why centripetal acceleration exists AND what it is
- 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
what does centripetal mean
acts towards the centre of a circular path
draw a diagram of the different forces acting on an object in circular motion
angular displacement def
The change in angle, in radians, of a body as it rotates around a circle
What is angular displacement the ratio of
radian def
The angle subtended at the centre of a circle by an arc equal in length to the radius of the circle
what do the components of the angular displacement equation mean
what is the angle in radians of 360 degrees
2 pi
what is the equation to convert from degrees to radians
angular speed def
The rate of change in angular displacement with respect to time
Why is an object moving in a circle accelerating?
- 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
What do the components of the angular speed equation mean?
What does the angular speed equation say about circular motion?
- 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 ⍵)
centripetal acceleration def
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
Describe the two equations which combine to form the centripetal acceleration equation
What are the components of the equation, a=vw
a = centripetal acceleration (m s−2)
v = linear speed (m s−1)
⍵ = angular speed (rad s−1)
centripetal force def
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.
What do the components of the centripetal force equation mean?
does the centripetal force act in the same direction an centripetal acceleration?
yes
what are 3 examples of centripetal forces
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
