Two small blocks P and Q of masses and are attached to light
PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
Two small blocks P and Q of masses m and 2m are attached to light, inextensible strings of lengths r and 21r respectively. Each block is whirled in a horizontal circle on a smooth table, the planes of the two circles being the same. Block P moves with constant speed v while block Q moves with constant speed 3v.
(i) Derive expressions for the tensions TP and TQ in the strings of blocks P and Q in terms of m, v and r.
(ii) Hence obtain the numerical ratio TP:TQ.
(iii) The radius of the circular path of block P is now slowly reduced to 0.75r while its speed v remains unchanged. By what factor does TP change as a result of this adjustment?