# need help sketching signal in time domain!

Discussion in 'Homework Help' started by becca02, Mar 10, 2009.

1. ### becca02 Thread Starter Member

Jan 28, 2009
10
0
for my homework, i am given the signal:

v(t) = -2 + 5cos(2pi200t + pi/4) - 2cos(2pi500t - pi/3)

Ive sketched the magnitude, phase, and power spectra. the total signal power in Watts came out to be 4W + 12.5W + 2W = 18.5W

and so the RMS voltage is P=VRMS^2/1Ω => VRMS = sqrt(18.5) = 4.301V

Now, my questions for the rest of this problem are as follows

1) if a 5kΩ resistor is applied to the signal, what is the average power dissipated on the resistor?

2) sketch the signal in time domain and determine its period, frequency, and average value (i think i just really need help on how to sketch it)

any help would greatly be appreciated !!

2. ### mik3 Senior Member

Feb 4, 2008
4,846
63
You can plot each part of the signal on the same plot individually and then find the resultant signal by summing the others. However, this is quite hard, thus you can use a software which plots graphs to make it.