A simple pendulum

The tension at the lowest point is given as 1.4N

Given

The length of the bob is given as 50 cm; the ball is pulled at a distance of 60 cm, making the angle of 37^o.

Formula Used

The formula for the total energy in terms of kinetic and potential energy is given as

&

where

The is the total energy in terms of kinetic and potential energy, m is the mass of the object, g is the acceleration in terms of gravity and r is the length of the rod/thread attached with the bob, m is the mass of the bob, is the velocity of the bob.

Explanation

The energy at the point which is lowest in the bob circulation is given as and the position of bob at an angle of 37^o, from the normal is given as point. Thereby, equating the energies together we get the velocity as

Hence, the tension is taken as