A 1 kg mass is projected down a rough circular track (radius = 2.0 m) placed in vertical plane as shown. The speed of the mass at point A is 3 m/s and at point B, it is 6.0 m/s. How much work is done on the mass between A and B by the force of friction?
Conservation of energy priniciple
KE at A =
Loss in PE between A and B =
Gain in KE from A to B if there had been no friction = 20 J
Total KE at B if there had been no friction = 4.5 +20 = 24.5 J
But actual KE at B =
Loss in energy duet to friction = 24.5 -18 = 6.5 J