Question

A Simple pendulum having a Bob of mass M is suspended from the ceiling of a car used in stunt film shooting in a car moves up along an inclined Cliff at a speed v and makes a jump to leave the Cliff and lands at some distance. let r be the maximum height of the car from the top of the Cliff. the tension in the in the string when the car is in air..plz explain with a figure.

Answer 1

I think explanations is simple.
During the jump of the car from the cliff its trajectory is like a projectile and from the maximum height it is freely falling under gravity with an acceleration g downward. Taking it as frame of reference, it is a non-inertial frame of reference. So a pseudo force equal to mg has to be applied to the bob in upward direction which neutralizes the weight and making it zero. So tension in the string is zero.
No need of figures, you can understand it just by solution