# Math in physics help

1. Mar 28, 2005

### waywardtigerlily

In a certain RLC circuit, the rms current is 6.72A, the rms voltage is 230V, and the current leads the voltage by 55.9 Degrees.
a)what is the resistance of the circuit?
b)calculate the total XL-Xc
c)Calc. the average power dissipated in the circuit.

a) 1.92E1 Ohms
b)?????
c)8.665E2 J

I can't figure out b! I tried using

tan x = X/R
tan 55.9 = (Xl-Xc)/(1.92E1 Ohm)
But this did not give me the right answer...maybe i am just doing the math wrong here....would you do this to solve for (XL-Xc)?
(1.92E1 Ohm)tan 55.9 = "x" ?
Thanks

2. Mar 28, 2005

### Andrew Mason

Note: The power is in units of energy / time. $VIcos\phi = P = I^2R$, so it is 867 J/sec.