The bob of a pendulum is released from a horizontal position. If the length of the pendulum is 1.5 m, what is the speed with which the bob arrives at the lowermost point, given that it dissipated 5% of its initial energy against air resistance?

Asked by Pragya Singh | 1 year ago |  151

1 Answer

Solution :-

Length of the pendulum, l= 1.5 m

Potential of the bob at the horizontal position = mgh = mgl

The initial energy dissipated against air resistance when the bob moves from the horizontal position to the lowermost point= 5%

The total kinetic energy of the bob at the lowermost position = 95% of the total potential energy at the horizontal position

(\( \dfrac{1}{2}\))mv2 = (\( \dfrac{95}{100}\)) mgl

v2 =2 [(\( \dfrac{95}{100}\)) x 9.8 x 1.5]

v2 =2 ( 13.965) = 27.93

v = \( \sqrt{27.93}\) = 5.28 m/s

Answered by Pragya Singh | 1 year ago

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