A particle passes through a fixed point O with velocity 10 m / s , moves with a constant retardation of 5 m / s 2 for 3 s and thereafter moves with constant velocity. How long after leaving O does it

Question

A particle passes through a fixed point O with velocity 10 m / s , moves with a constant retardation of 5 m / s 2 for 3 s and thereafter moves with constant velocity. How long after leaving O does it return to O ?

TestHub · Accepted Answer

After 3 s the velocity is 10 − 15 = − 5 m/s and the displacement is 10 ( 3 ) − 2 1 ​ ( 5 ) ( 9 ) = 7.5 m. Returning at a steady 5 m/s takes 5 7.5 ​ = 1.5 s more, so the total time is 4.5 s. Option B.

Physics - Kinematics Question with Solution | TestHub

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