Summary:: Solving series-parallel circuits using current and voltage divider rule
For the attached circuit, I need to determine the voltage drop across R4 using the voltage divider rule.
So far, I have determined total resistance to be R = 383Ω, total current I = 0.03A, and I3 = 0.023A.
I...
I sort of thought I had sine & cos mixed up..
Vpw = (-4.5sin30)x +(4.5cos30)y
Vfp = 0x + (-1.5)y
Vfw = -2.25x + 2.4y
= 3.28m/s and 43.17 + 30 = 73.17 west of north
I think I'm focusing on the person walking North relative to the ferry and I keep wanting to place that vector pointing north when it is in fact not north relative to the water.
Ok,that makes more sense. Thing is, when I change the formula from Vpw = Vpf + Vfw to
Vfw = Vpw - Vpf, I'm not sure if I'm still supposed to switch the pw to wp (and therefore the direction) and I'm pretty sure the x component for Vpw would still be negative as well. So,lots of negatives...
This is what I have:
Vfw = Vpf + Vpw
= -Vfp + Vpw
Vpf = 0x = (1.5)y
Vpw = (-4.5 cos 30)x + (4.5 sin 30)y
Vfw = -3.90x + 0.75y
= 15.8 m/s at 10.9 degrees west of north
I drew a diagram which is basically the person walking north (positive x axis) from the origin and the then for the person relative to the water a vector 30 degrees from the north axis (to the left of the y axis) also starting at the origin.
I am confused as to using the displacement diagrams...
(pw is person to water, pf is person to ferry, fw is ferry to water)
I get Vpw = Vpf + Vfw. Therefore Vfw = Vpw + Vpf, which is
Vfw = -Vwp + Vpf. I also have that the x component of Vpw is negative.
I think I'm getting confused with either the order of the formula or the negative negatives (or...