Paper 3 · circular motion and projectile motion
A pendulum bob of mass 72.0 g is rotated at a constant speed of 4.5 m/s in a vertical circle of radius 50.0 cm. Calculate the centripetal force on the bob.
Model answer
2.92 N
Also accepted: 2.9 N, 2,92 N
Explanation: Centripetal force F = Mv^2/r = (0.072 x 4.5^2)/0.5 = 2.92 N.
Derived from ZIMSEC Physics Paper 3, June 2003, Q1