capacitor

Hi. Can someone please check these two answers? (a) seems very low and (b) seems very high to me. A 0.22 micro-F capacitor is charged by a 1.5-V battery. After being charged, the capacitor is connected to a small electric motor. Assuming 100% efficiency, (a) to what height can the motor lift a 5.0-g mass? (b) What initial voltage must the capacitor have if it is to lift a 5.0-g mass through a height of 1.0 cm? My solutions: (a) C = 0.22 micro-F = 0.22 x 10^-6 F V = 1.5 V m = 5.0 g = 5.0 x 10^-3 kg h = ? Q = CV = 3.3 x 10^-7 U = (1/2)QV = 2.5 x 10^-7 J ANSWER: U = mgy , y = U/mg = 5.1 x 10^-6 m (b) V = ? m = 5.0 x 10^-3 kg C = 0.22 x 10^-6 h = 1 cm = 0.01 m ... click for more

Capacitors

Two capacitors are connected in parallel. If a third capacitor is connected in parallel with the other two, does the equivalent capacitance increase, decrease, or remain the same? Explain.

Fuses & Circuits

A fuse is a device to protect a circuit from the effects of a large current. The fuse is a small strip of metal that burns through when the current exceeds a certain value, thus producing an open circuit. Should a fuse be connected in series or in parallel with the circuit it is intended to protect? Explain.

RC circuit

Hi. Can someone please walk me through how to do this problem? Consider an RC circuit with epsilon = 12.0 V, R = 175 ohms, and C = 55.7 micro-F. Find (a) the time constant for the circuit, (b) the maximum charge on the capacitor, and (c) the initial current in the circuit. Thank you.

capacitors

Hi. Can someone please walk me through how to do the following problem? Two capacitors, one 7.5 micro-F and the other 15 micro-F are connected in a series across a 12-V battery. (a) Find the equivalent capacitance of the two capacitors. (b) Which capacitor stores more charge. Explain. (c) Find the charge stored on each capacitor. Thank you.