A small smooth bead is released from rest at the top of a fixed quarter-circular wire…
PHYSICS · Subjective · CBSE · Physics · Motion in a Plane · Motion in a Plane
Problem
A small smooth bead is released from rest at the top of a fixed quarter-circular wire track of radius R lying in a vertical plane. The top point of the track is horizontally to the left of its bottom point, so that the bead moves through a 90∘ arc under gravity.
(a) Write the position vectors (with respect to the centre of the circle) of the bead at the start and at the end of the motion.
(b) Obtain the bead’s overall displacement vector for the motion and hence find its magnitude.
(c) Using your result from part (b), compute the work done by the gravitational force on the bead during its slide and state whether it is positive or negative.
(d) What is the work done by the normal reaction exerted by the track? Give a reason.