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naatp
The quantity of a charge Q that passes through a surface at time t (seconds), is given by Q=t^3 -2t^2 +6t +2. The current is defined as the rate of change of the charges with respect to t. Find the current when t=2
\[i(t)=\frac{ dq }{dt }=3t^2-4t+6\] \[i(2)=3(2)^2-4(2)+6=10A\]
Apparently the answer is \[\frac{ 3 }{ 10\Pi } \] cm/s