Question

The bob A of a simple pendulum is released from a horizontal position A as shownin in figure. If the length of the pendulum is 1.5m , what is the speed with which the bob arrives at the lowermost point B, given that it dissipates `5%` of its initial energy against air resistance ?

A. `3.14`
B. `5.28`
C. `1.54`
D. `8.26`

Answer 1

Correct Answer - B
According to the law of conservation of energy, the total energy of the system remains constant.
`95 %` of `P.E_(i) = K.E_(f)`
i.e., `(1)/(2) m v^(2) = (95)/(100) xx mgl`.