A small stone is tied to one end of a light string and whirled in a horizontal circle…
PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
A small stone is tied to one end of a light string and whirled in a horizontal circle of radius r on a smooth table with constant speed v. Answer the following questions related to its motion.
(i) Define uniform circular motion.
(ii) When the stone is momentarily at point P on the circle, draw a neat labelled diagram showing the radius vector r, the instantaneous velocity vector v, and the acceleration vector a.
(iii) Explain clearly why the stone experiences an acceleration even though its speed remains constant throughout the motion.
(iv) If the string suddenly breaks when the stone is at point P, describe the subsequent path of the stone and justify your answer on the basis of the direction of its velocity vector at that instant.