Determine time the time when Q=0C

[Lukáš Dufka]

Hi, I have a question. Electric current in the circuit according to the relation I=1-10cos(50t). Determine the time when the Q=0 C.

I used:

 

I =dQ/dt 

Q(t) = ∫ Idt 

= ∫(1-10cos(50t))dt 

= t - (10/50)sin(50t) + C 

= t - 0.2sin(50t) + C

 

But what now ? I donť known how can i calculate the time... Someone told me that i must find the interval of definite integral... from t=0 to t=?....

 

Thank you for reply. 

[FizziksGuy]

Right, I would integrate from time t=0 to some final time t=t, so your limits of integration are 0 to t.