Topic 2A - UCM

Question 1

What is uniform circular motion?

Answer 1

A object travelling in a circular path at a constant speed

Question 2

What is centripetal acceleration?

Answer 2

‘centre seeking’ acceleration that is always perpendicular to the direction of travel of the object.
With UCM it is always towards the centre of the circle.

Question 3

Given a circle, how should the velocity of an object at any point on that circle be drawn?

Answer 3

As a tangent to the circle.

Length should be consistent for entire circumference.

Question 4

What is the period of something travelling with UCM?

Answer 4

The time taken to complete one revolution or orbit. (in seconds)

Question 5

Equation for velocity with UCM

Answer 5

V = d pi / T
Velocity =  pi x diameter / period

Question 6

Equation for Centripetal force

Answer 6

F = mv(squared) / r

Force = mass x squared velocity / radius

Question 7

Equation for centripetal acceleration

Answer 7

a = v(squared) / r

acceleration = squared velocity / radius

Question 8

How does a banked curve decrease the reliance on frictional forces?

Answer 8

The normal force of the vehicle is no longer vertical
It can be split into components.
The vertical component is cancel out by the weight f the car.
However, the horizontal component points towards the centre of the circular path and thus provides some of the centripetal acceleration needed for UCM.