# Physics

posted by .

A 7uF capacitor is charged to a potential difference of 110V The electrical energy stoed in the capacitor is
but I used C=Q/V and keep getting 7.7x10^-4

also A particle of charge Q and mass m is accelerated from rest through a potential difference V, attaining kinetic energy K. What is the kinetic energy of a particle of charge 2Q and mass m/2 that is accelerated under the same conditions? (Answer was given as 2K but i got 4k)

• Physics -

W = 0.5CV^2,
W=0.5 * 7*10^-6 * (110)^2 = 4.23*10^-2.

## Similar Questions

1. ### physics

Having trouble with this one: A capacitor having a capacitance of 10uF is charged by 100v battery. A.)Calculate the charge on the capacitor?
2. ### physics

A source of e.m.f 110v and frequency 60hz is connected to a resistor, an indicator and a capacitor in series. When the current in the capacitor is 2A.the potential difference across the resistor is 80v and that across the inductor …
3. ### Physics

A capacitor network has two capacitors in series: 150nF and 120nF. The potential difference between point a on the outer side of the 150nF capacitor and point b on the outer side of the 120nF capacitor is 120nF. a) total charge of …
4. ### Physics Help!

A 220 uF capacitor with a 10% tolerance rating is charged. The voltage across the capacitor is measured to be 110 +/- 5.5 volt. Calculate the electrical charge stored in the capacitor. Estimate the error in the charge by propagating …
5. ### Physics

Capacitors are used in many applications where you need to supply a short burst of energy. A 143 μF capacitor in an electronic flash lamp supplies an average power of 12.6 kW to the lamp for 2.95 ms. To what potential difference …
6. ### physics

You have a parallel plate capacitor (with air between its plates) which is attached to a voltage source until the capacitor is fully charged. (a)After detaching the capcitor from the voltage source, you move the capacitor's plates …
7. ### Physics

A capacitor has a charge of 5 µC when charged by a potential difference of 1.5 V. What is the capacitance of the capacitor?
8. ### Physics: Potential Difference

Two capacitors are identical, except that one is empty and the other is filled with a dielectric (k = 3.6). The empty capacitor is connected to a 15 -V battery. What must be the potential difference across the plates of the capacitor …
9. ### Phys1

A 2μF capacitor is charged to 50V and then connected in parallel with a 4μF capacitor charged to 100 V.?
10. ### physics

An isolated capacitor of unknown capacitance has been charged to a potential difference of 100 V. When the charged capacitor is then connected in parallel to an un- charged 10.0 μF capacitor, the potential difference across the …

More Similar Questions