A particle is moving in a straight line. The variation of position ‘x’ as a function of time ‘t’ is given as x = (t³ – 6t² + 20t + 15) m. The velocity of the body when its acceleration becomes zero is :
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Question

A particle is moving in a straight line. The variation of position ‘x’ as a function of time ‘t’ is given as x = (t³ – 6t² + 20t + 15) m. The velocity of the body when its acceleration becomes zero is :

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G1 Physics · Accepted Answer

x = t³ – 6t² + 20t + 15 v = dx/dt = 3t² – 12t + 20 a = dv/dt = 6t – 12 When a = 0 6t – 12 = 0; t = 2 sec At t = 2 sec v = 3(2)² – 12(2) + 20 v = 8 m/s