# Simple i suppose ?

1. Dec 12, 2009

### faraznizamani

This is bugging me for some reason .. can any one help me with this ?

the current flowing through an element is
i= {2A, 0<t<1
2t^2, t>1}
calculate the charge entering the element from t=0 to t=2 second

2. Dec 12, 2009

### CompuChip

What is the relation between charge, current and time?

3. Dec 12, 2009

### faraznizamani

I have no other data regarding the question :/ can you help me ?

4. Dec 12, 2009

### CompuChip

Well, current is simply a moving charge. In fact it is defined as the rate at which charge passes:
$$I = \frac{\Delta Q}{\Delta t}$$
or, in the limit of vanishing $\Delta t$,
I(t) = dQ/dt (the derivative).

Try integrating both sides of that equation.