A particle moves in a straight line and passes through O , a fixed point on the line, with a velocity of 6 m / s . The particle moves with a constant retardation of 2 m / s 2 for 4 seconds and thereaf

Question

A particle moves in a straight line and passes through O , a fixed point on the line, with a velocity of 6 m / s . The particle moves with a constant retardation of 2 m / s 2 for 4 seconds and thereafter moves with constant velocity. How long after leaving O does the particle return to O ?

TestHub · Accepted Answer

After 4 s the velocity is 6 − 2 ( 4 ) = − 2 m/s and the displacement is 6 ( 4 ) − 2 1 ​ ( 2 ) ( 16 ) = 8 m ahead of O . Moving back at a constant 2 m/s, the particle needs 2 8 ​ = 4 s more, so it returns to O after 4 + 4 = 8 s. Option A.

Physics - Kinematics Question with Solution | TestHub

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