The flash unit in a camera uses a 3.0 V battery to charge acapacitor. The capacitor is then discharged through a flashlamp.The discharge takes 7 µs, andthe average power dissipated in the flashlamp is 8 W. What is the capacitance of the capacitor?

Respuesta :

Answer:

[tex]C=2.54\cdot 10^5\ F[/tex]

Explanation:

Energy Stored on a Capacitor

This energy is stored in the electric field present when a voltage V is applied to a capacitor C. It can be computed by the formula

[tex]\displaystyle E=\frac{CV^2}{2}[/tex]

We can compute the energy by knowing the power dissipated in the flashlamp is P=8 W in a time of [tex]7 \mu s=7\cdot 10^{-6}\ sec[/tex]

[tex]\displaystyle E=\frac{P}{t}=\frac{8\ W}{7\cdot 10^{-6}\ sec}=1.14\cdot 10^6\ J[/tex]

Solving the first equation for C

[tex]\displaystyle C=\frac{2E}{V^2}[/tex]

[tex]\displaystyle C=\frac{2\times 1.14\cdot 10^6}{3^2}[/tex]

[tex]\boxed{C=2.54\cdot 10^5\ F}[/tex]