Centripetal acceleration and forceEdexcel International A Level Physics: Flashcards

What these 12 flashcards ask

State the equations for centripetal acceleration.
State the equations for centripetal force.
Why does an object moving in a circle at constant speed accelerate?
What is the direction of the acceleration in circular motion at constant speed?
What is a centripetal force?
Is centripetal force a separate, new force?
State the link between v and ω.
Convert a frequency f into an angular speed.
Convert 3000 rev min⁻¹ to rad s⁻¹.
In the vector-diagram derivation, what is Δv for a small angle Δθ?
What is the arc length equation used in the derivation?
What happens to the centripetal force needed if the speed doubles at the same radius?

Exam questions on Centripetal acceleration and force

A ball of mass 0.25 kg is attached to a light string and whirled in a horizontal circle of radius 0.80 m on a frictionless table. The other end of the string is fixed at the centre of the circle and the ball moves at a constant speed of 4.0 m s⁻¹.
The ball moves at constant speed. Explain why a resultant force acts on it and state the direction of that force.2 marks
A laboratory centrifuge spins at a steady 3000 revolutions per minute. A sample tube is held so that its contents are at a distance of 0.12 m from the axis of rotation.
The tube wall must provide the force needed to keep 5.0 g of sediment moving in the circle at this radius. Calculate this force.2 marks
A car of mass 1200 kg drives round a flat, circular bend of radius 45 m. On a dry road the maximum sideways friction force the tyres can provide is 7.8 kN.
Calculate the maximum speed at which the car can take the bend without skidding.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).