A) \[24 m/{{s}^{2}}\]
B) Zero
C) \[6 m/{{s}^{2}}\]
D) \[12 m/{{s}^{2}}\]
Correct Answer: D
Solution :
\[\operatorname{x}=8+12t-{{t}^{3}}\] \[\operatorname{v}=\frac{dx}{dt}=12-3{{t}^{2}}\] When v=0 \[12-3{{t}^{2}}=0\] t=2 sec [at (t=2s) velocity becomes zero] \[\operatorname{a}\left( t=2 \right)=\frac{dv}{dt}\frac{d}{dt}[12-3{{t}^{2}}]=0-6t=6t\] \[a=-6\times 2\] \[a=-12m/{{s}^{2}}\] (-ve sing implies retardation)You need to login to perform this action.
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