05/10 - Lots of Examples (No Lab Today)

Today, we were supposed to do a lab; however, we got really short on time because nobody could remember how to do trig stuff, so we just did lots of examples on our white boards.

In Class Examples

1. First, we looked at a problem Mason made up on his white-board, where we wrote the equation for a sine graph, then shifted it over by .0012.

2. Calculate the phase angle between v 1 = − 10 cos(ωt + 50°) and v 2 =12 sin(ωt − 10°). State which sinusoid is leading.

3. Evaluate the complex number: (30, 30° - (-20, 70°))^-1

4. In this example, we were given four different sinusoidal voltages and asked to convert them into phasor form.

5. Find the sinusoids represented by these phasors: (a) V = j8e−j20o, (b) I = − 3 + j4

6. If v 1 = − 10 sin(ωt + 30o) and v 2 = 20 cos(ωt − 45o), find V = v 1 + v 2 .

7. The voltage v = 12 cos(60t + 45o) is applied to a 0.1-H inductor. Find the steady-state current through the inductor.