A simple pendulum of length
is suspended from the ceiling of a car moving with a speed u on a circular horizontal road of radius r. (a) Find the tension in the string when it is at rest with respect to the car. (b) Find the time period of small oscillation.
(a) ma
(b)
where 

(a)when pendulum is in rest with respect to car, the free body diagram will be as follows
The tension in the string will be due to force due to gravity and
Force due to centripetal force



Here
is the acceleration on the bob
(b) Time period of the small oscillation

From previous problem, we know

