NEET-XII-Physics
07: Circular Motion
- #14The bob of a simple pendulum of length 1 m has mass 100 g and a speed of 1.4 m/s at the lowest point in its path. Find the tension in the string at this instant.Ans :
Given:
Mass of the bob = m = 100 gm = 0.1 kg
Length of the string = r = 1 m
Speed of bob at the lowest point in its path = 1.4 m/s
Let T be the tension in the string.
From the free body diagram, we get:
`` T=mg+\frac{m{v}^{2}}{r}``
`` =\left(\frac{1}{10}\right)\times 9.8+\frac{(1.4{)}^{2}}{10}``
`` =0.98+0.196``
`` =1.176\approx 1.2\,\mathrm{\,N \,}``
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