When a particle travels in a circle of radius r, at constant speed v, what is its acceleration

v2/r, towards the center of the circle.Remember that acceleration is the rate of change of velocity, not merely of speed. This means that the change in direction is important. In a unit of time, the velocity vector will rotate by a small angle. This angle is proportional to the angular velocity (w) and to the size of the time unit. This means that the acceleration has magnitude vw. Since w=v/r, this is v2/r. Since the speed is constant, we know that the force is acting perpendicular to the direction of motion, so we finally have v2/r towards the center of the circle.

Related Physics A Level answers

All answers ▸

A block of mass (m) is placed on a rough slope inclined at an angle (a) to the horizontal, find an expression in terms of (a) for the smallest coefficient of friction (x), such that the block does not fall down the slope.


This is a question on the photoelectric effect: For potassium, the work function is 3.65E-19J. Find the maximum wavelength of light that will cause photoelectrons to be emitted when shone onto potassium.


A transmitter from a researcher's boat sends a signal to the seabed of waves speed 300m/s and it takes 5 seconds for the signal to return back to the boat. Calculate the depth of the sea there.


What is the Quark structure, Baryon number, and antiparticle of a kaon, K+, which has a strangeness of 1.