Question

8. A simple pendulum of length 1 has a bob of mass m. The work done in projecting
the bob horizontally from the mean position to give it an angular displacement of
60° is



​

Answer 1

Explanation:

Length of simple pendulum =1m

Mass =1wgm=0.1kg

It is displaced through as angle of 60 for vertical

Height of pendulum at starting position = length (1−ws60)

=1(1−0.5)

=0.5m

Potential energy =mgh=0.1×10×0.5=0.55

when it is released and it reaches mean position its potential energy at starting point is converted to kinetic energy.

so K.E. of bob at mean position =0.55.

Hence, the answer is