How is a particle moving in circular motion accelerating but not varying speed?

When a particle moves in circular motion, the resultant centripetal force acts radially towards the centre of the circle. Since there is a force there must be an acceleration on the particle due to Newtons 2nd law. However if you were to analyse the particles movement you would observe that the time period stays constant, showing that the speed is constant. Therefore the question is, how is an acclerating particle not varying speed? The answer behind this comes from the fact that acceleration and velocity are vector quantities, meaning they have a magnitude and direction. The velocity of the particle acts in the direction of the tangent to the circle and is therefore perpendicular to the force. Due to the force and velocity being perpendicular from one another there is no work done on the particle, because the particle doesn't change energy then it cannot change speed. The change in velocity comes from the particle's velocity changing direction around the circle rather than its magnitude. 

MS
Answered by Max S. Physics tutor

3389 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What is the difference between linearly, directly and inversely proportional relationships?


What is a vector?


Explain the photoelectric effect, when does it occur and what is its significance in understanding the nature of light ? (6)


Describe the process of nuclear fission is induced


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences