An experimenter is inside a train. He observes that minimum speed at lowest position needed by a pendulum bob to complete a vertical circle is 10 m/s. Calculate the minimum speed (u) needed at the lowest position so as to complete the vertical circle when the train is moving horizontally at an acceleration of `a = 7.5 m//s^2`. Find the maximum tension in the string during the motion. [`g = 10 m//s^2`].

Answer

`u=sqrt(115) m//s`