Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Size and Direction Three

  1. Mar 24, 2007 #1
    Please help!!!

    My problem is: (with figure attached, the figure explains the majority of the ptorblem)
    (a) What is the size and direction of current i1 in Fig. 27-40, where each resistance is 2.2 and V1 = 18 V?

    (b) What is the power of the 18 V battery, and is energy being supplied or absorbed by the battery?

    (c) What is the power of the 10 V battery, and is energy being supplied or absorbed by the battery?

    (d) What is the power of the 5.0 V battery, and is energy being supplied or absorbed by the battery?

    Relevant Equations
    V=iR

    For part (a) I'm having trouble firguring out which resistances to use. Do I use all of the resistances and add them up according to whether they are parallel or perpendicular? Then, when I get the resistance that I need, do I just use the 10 V battery as my voltage to calculate the current? I tried adding all of the resistances and I got 8.64 ohms. Is this correct?

    For part (b) I need to know again what resistance to use to calculate the current, which I would need to calculate power. If I can get some help on (b), I can probably do (c) and (d) by myself.
     

    Attached Files:

    Last edited: Mar 24, 2007
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted