Physics HELP!

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i need help on this please as soon as possible. i need to know it by tomorrow and i cant figure out how to do it.

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Light bulbs with the power ratings (at 120V) are connected in a circuit. a) what current does the voltage source deliver to the circuit? b) find the power dissipated by each bulb. (Take the bulb resistances to be the values when each bulb has a voltage of 120V.)

ok. so i got part a) I= .0851A
but part b is what i need help with.
so im not really sure how to find the "power dissipated by each bulb"
im quite clueless actually i've gotten so many problems that ask this and i go to do something and i do it all wrong. the answers for part be are suppose to be
40W bulb dissipates 2.6W
100W bulb dissipates .408W
60W bulb dissipates .245W
15W bulb dissipates 6.952W

can someone please tell me how they got these answers and show me how to do it?. it would be greatly appreciated.

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Re: Physics HELP!

mitnick2t wrote:

i need help on this please as soon as possible. i need to know it by tomorrow and i cant figure out how to do it.

http://img27.imageshack.us/my.php?image=physics2za.jpg

Light bulbs with the power ratings (at 120V) are connected in a circuit. a) what current does the voltage source deliver to the circuit? b) find the power dissipated by each bulb. (Take the bulb resistances to be the values when each bulb has a voltage of 120V.)

ok. so i got part a) I= .0851A
but part b is what i need help with.
so im not really sure how to find the "power dissipated by each bulb"
im quite clueless actually i've gotten so many problems that ask this and i go to do something and i do it all wrong. the answers for part be are suppose to be
40W bulb dissipates 2.6W
100W bulb dissipates .408W
60W bulb dissipates .245W
15W bulb dissipates 6.952W

can someone please tell me how they got these answers and show me how to do it?. it would be greatly appreciated.

No. Die the slow death. Our thoughts will be with you.

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In order to find the current you have already found the resistances of each bulb and the parallel pair. So apportion the voltage drop in the ratio of each of those resistances.

e.g. V(15) = 32/47 x 120 = 81.702

so W(15) = V(15) x I
= 81.702 x .0851
= 6.952

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Physics HELP!

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