16 : Circular motion Flashcards
1
Q
angular velocity
A
- rate of change of angle
- ω = θ/t
- when a t = one full revolution
- ω = 2π /T
- =2π f
- rads^ -1
2
Q
centripetal force
A
- always acts towards centre of a circle
- acting perpendicular to velocity
- no work is done on object and as a result speed and kinetic energy is constant
3
Q
linear velocity
A
- s= d/t
- in one complete rotation
- v= 2πr / T
- and as ω = 2π /T
- linear velocity = rω
4
Q
comparing objects velocity
A
- same time to complete one rotation
- doubling the radius the line velocity is also doubled
- but all have the same angular velocity
5
Q
centripetal acceleration
A
- the acceleration of any object travelling in a circular path at a constant speed = centripetal acceleration
- a = v^ 2 /r
- or a = ω^ 2 r
- speed is constant but velocity is constantly changing as its direction changes
- always directed towards the centre of the circle
6
Q
acceleration and force
A
- objects speed remains constant becasue the component of the frce acting on the object in the direction of motion is zero
- f = mv^ 2/ r
- or F =mω^ 2 r
- acts towards the centre of the circular path
7
Q
Banked surfaces
A
- the greater the sped of an object on a circular path the greater the centripetal force required to follow this path
- the horizontal component of normal contact force together with frictional force provide the centripetal fore