16. Circular motion

Question 1

What is a radian?

Answer 1

The angle subtended by a circle arc with a length equal to the radius of the circle (approximately 57.3˚)

Question 2

What is Angular velocity?

Answer 2

The rate of change of angle for an object moving in a circular path - w

Question 3

What is centripetal force?

Answer 3

A force that keeps a body moving with a constant speed in a circular path

Question 4

What is Centripetal acceleration?

Answer 4

The acceleration of any object travelling in a circular path at constant sped, which always acts towards the centre of the circle

Question 5

What equations do i need to know?

Answer 5

degrees to radians = ÷ 180/π

w = 2π/T
w = 2πf

v = 2πr/T
v = rw

a = v^2/r
a = w^2r

F = mv^2/r
F = mw^2r

1revs^-1 = 2π radians
1/2π revs^-1 = 1 radian

Question 6

What is a radian and what is the conversion?

Answer 6

Radian = the angle subtended by a circular arc with a length equal to the radius of the circle ≈ 57.3˚

360˚ = 2π

degrees to radians = ÷ 180/π