The distance moved by the particle in time t is given b
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The distance moved by the particle in time t is given by x=t3−12t2+6t+8. At the instant when its acceleration is zero, then the velocity is
A.
42
B.
-42
C.
48
D.
-48
Please scroll down to see the correct answer and solution guide.
Right Answer is: B
SOLUTION
We have,
x=t3−12t2+6t+8
⇒dxdt=3t2−24t+6andd2xdt2=6t−24
Now, Acceleration =0
⇒d2xdt2=0⇒6t−24=0⇒t=4
Att=4, we have
Velocity =(dxdt)r−4=3×42−24×4+6=−42.
Hence (b) is the correct answer.