A student is modelling the decay of charge for a capacitor discharging through a resistor using the equation:
ΔQΔt=−0.4Q \frac{\Delta Q}{\Delta t} = -0.4 Q ΔtΔQ=−0.4QThe student decides to use Δt=0.5 s\Delta t = 0.5\text{ s}Δt=0.5 s. The initial charge on the capacitor is 2000 μC2000\ \mu\text{C}2000 μC.
Part of the modelling spreadsheet from the student is shown below:
| t / st\text{ / s}t / s | Charge Q Q\,Q left on capacitor at time t / μCt\text{ / }\mu\text{C}t / μC | Charge ΔQ \Delta Q\,ΔQ decaying in the next 0.5 s / μC0.5\text{ s}\text{ / }\mu\text{C}0.5 s / μC |
|---|---|---|
| 0 | 2000 | 400 |
| 0.5 | 1600 | |
| 1.0 | ||
| 1.5 |
What is the value of Q Q\,Q in μC\mu\text{C}μC at t=1.5 st = 1.5\text{ s}t=1.5 s?
100010001000
102410241024
128012801280
140014001400
