Unit 4: Motion in a circle Flashcards
What is uniform circular motion?
When an object rotates at a steady rate
What is the formula for frequency?
f = 1/T where T is the time for one rotation
What is the formula for velocity and how is it derived?
v = 2πr/T and it is derived through distance travelled which is the circumference/time taken for one rotation
How do you calculate the number of rotations in one minute?
Multiply the frequency of rotation by 60
What does an object in uniform circular motion turn through an angle of each second?
2π/T radians where T is the time for one complete rotation
What are the formulas for the angular displacement of an object in time t?
2πt/T or 2πft
What is angular speed defined as?
The angular displacement per second
What is the formula for angular speed?
ω = 2πf
What is ω measured in?
Radians per second
What is the formula for velocity in terms of ω?
v = rω
What is the formula for the length of an arc?
s = rθ
Why does an object accelerate when it is travelling in a circle?
The velocity of an object moving around a circle at constant speed continuously changes direction
What is acceleration?
The change of velocity per second
In which direction is the velocity of an object at any point in a circle?
Along the tangent to the circle at that point
Why is the acceleration towards the centre of the circle and what is this acceleration called?
The change in direction of the velocity is towards the centre of the circle therefore the acceleration is towards the centre of the circle and this type of acceleration is centripetal acceleration
What is the formula for centripetal acceleration in terms of v?
a = v^2/r