A pendulum bob of mass 0.20kg is suspended by a string 0.80m long. The bob is pulled aside so that it makes an angular displacement of 4.0∘ from the mean position and is then held momentarily.
(a) Convert this angular displacement to the corresponding arc–length displacement s.
(b) Calculate the magnitude of the restoring force acting on the bob at this instant.
(c) Determine the tangential (linear) acceleration of the bob at this position.