Uniform circular motion Flashcards
1
Q
When is an object in uniform circular motion?
A
an object rotating at a steady rate
2
Q
Why is 360 degrees 2π radians?
A
- arc length = 2πr
- 2πr / r = 2π
- so there are 2π radians in a complete circle
3
Q
What is angular speed?
A
- ω
- angular displacement per unit time
4
Q
What is the frequency of rotation?
A
1 / T
where T is time for rotation
5
Q
Why are objects travelling in circles always acceletating?
A
- velocity always changing
- even when going at constant speed
- changing direction
6
Q
Why is it called centripetal acceleration?>
A
- always directed towards the centre of the circle
7
Q
What is angular displacement?
A
the angle an object in circular motion turns through = 2πft = 2πt/T
8
Q
What is centripetal force?
A
- the resultant force on an object moving around a circle at constant speed
- acts in same direction as centripetal acceleration
- e.g. tension in a string
- causes centripetal acceleration
