Question

A simple pendulum consists of a bob of mass m and a string of length r suspended from a peg p1

Answer 1

Q  - ->  A simple pendulum consists of a bob of mass m and a string of length R suspended from a peg P1 on the wall. A second peg P2 is fixed  vertically below the first one at a distance 3R/7 from it.The pendulum is drawn aside such that the string is horizontal and released. Calculate the maximum height (with respect to the lowest point) to which it rises

Given :

Mass of the bob = m

Length of the string = R

Distance between the pegs = 3R/7

To Find :

The maximum height reached by the pendulum

Solution :

• The potential energy of the bob at its lowest point = mgR

• The effective length of the string when it reaches height R  from the lowest position

               $=R-(\frac{3R}{7} )$

               $=\frac{4R}{7}$

• Maximum height upto which it rises

               $=R-\frac{4R}{7}$

               $=\frac{3R}{7}$

The maximum height reached by the pendulum is 3R/7.