Physics A2 - circular motion

State the equation to find centripetal acceleration

acceleration = velocity ^2 ÷ radius

State the equation to find the centripetal force

centripetal force = acceleration = mass x velocity ^2 ÷ radius

State the equation to find angular velocity

angular velocity = 2 x π x frequency ( 1 ÷ time period )

State the equation to find linear velocity

Linear velocity = angular velocity x radius

What is the unit of angular velocity

Rad s^-1

Write an expression for the Cf required on a vehicle going over the top of a curved bridge or hill

F = m x g - N where N = normal contact force exerted by the road on the vehicle & m= the vehicle's mass

Why do you feel heavier at the bottom of a loop the loop than at the top

Because what you experience as your weight is actually the normal contact force on you - the normal contact force on you is greater at the bottom than at the top

Define angular velocity

Rate of change of angle for an object moving in a circular path symbol w

Direction of the velocity of an object travelling in a circle at a constant speed

Along the tangent to the circle ( at its position )

When do you feel weightless

When the normal contact force on you is zero

Define angular frequency

A quantity used in oscillatory motion - equal to the product of frequency f & 2 pie

An object in circular motion is accelerating, despite travelling at a constant speed. how

It is constantly changing direction therefore constantly changing velocity & acceleration is defined as the rate of change of velocity

Measurements you'd make in whirling bung practical?

measure the radius of the circle with a ruler while the equipment is stationary; measure the time for multiple revolutions with a stopwatch then divide, to increase accuracy and reduce uncertainty; measure the masses of the bung and the hanger using an electronic balance

Where on loop the loop do you feel weightless & why

At the top when your weight = required CF contact force = 0 and when v = root g x r