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Two small wooden blocks are placed on a circular rotating table of radius 1 m at distance 10 cm and 60 cm from the centre of the table. The table is rotating with angular velocity 4 rad s-1 about its axis of rotation. Out of these two blocks which one continues to revolve with the table. Given μ = 0.2 |
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Answer» r = 1 m, ω = 4 rad s-1, μ = 0.2 The wooden block will continue to revolve with table if force of friction is equal to or greater than the centripetal force required by it. i.e., F ≥ {mv2}/{r} Since F = μR = μ mg Hence μ mg = mv2/r or, μ mg ≥ mr ω2 (∴ v = ωr) or mrω2 = μ mg or, r ≤ μg/ω2 or, r ≤ {0.2 x 9.8}/{16} ≤ 0.123 m Thus, the block placed at 100 cm will revolve with the table. |
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