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A truck starts from rest and accelerates uniformly at 2.0 m s^(-2).At t = 10 s, a stone is dropped by a person standing on the top of the truck (6 m high from the ground). What are the (a) velocity, and (b) acceleration of the stone at t = 11s ?(Neglect air resistance.) |
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Answer» SOLUTION :(a)Velocity of car ( at t = 10 s ) =` 0 + 2 x× 10 = 20 m s^(-1)` By the First Law, the HORIZONTAL component of velocity is` 20 m s^(-1)`throughout. Vertical component of velocity (at t = 11s) ` = 0 + 10 xx 1 = 10 ms^(-1)` Velocity of stone (at t = 11s) ` = sqrt( 20^2 + 10^2) = sqrt 500 = 22.4 ms^(-1)` at an angle of `tan^(-1) (1//2)` with the horizontal. (b) `10 ms^(-2)` vertically DOWNWARDS . |
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