A simple pendulum of length l and having a bob of mass M is suspended in a car. The car is moving on a circular track of radius R with a uniform speed v. If the pendulum makes small oscillations in a radial direction about its equilibrium position, what will be its time period ?

As the pendulum is osrillatingin the radial direction, it is acted upon by an additional acceleration equal to the centripetal acceleration of the car on the circular track of radius R, where v = uniform speed of the car. So, there are two accelerations acting on the pendulum in mutually perpendicular directions