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A particle is moving in a straight line with initial velocity `u` and uniform acceleration `f`. If the sum of the distances travelled in `t^(th) and (t + 1)^(th)` seconds is `100 cm`, then its velocity after `t` seconds, in `cm//s`, is.A. 20B. 30C. 50D. 80 |
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Answer» Correct Answer - C `a = f` `(dv)/(dt) = f " " rArr underset(u) overset(v)int dv = underset(0) overset(t) int fdt` `rArr v = u + ft` `v = (dx)/(dt) = u + ft` `rArr underset(0) overset(100)int dx = underset(t - 1)overset(t + 1)int (u + ft) dt rArr 2u + 2f t` `= 100 rArr u + ft = 50` ....(1) `v t sec rArr v = u + ft = 50 cm//s` by (1) |
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