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I know that this has to be an easy problem, but my teacher left us in December and we got stuck with an idiot who hasn't taught us anything since then......

How many 65-W light bulbs can be connected in parallel across a potential difference of 85V before the total current in the circuit exceeds 2.1 A?

[tex]\Sigma[/tex]1[tex]/[/tex]Req=1[tex]/R1[/tex]+1[tex]/R2[/tex]+1[tex]/R3[/tex]...

P=IV

V=IR

I can't get an answer that makes any sense, but this is what I tried to do.

P=65-W

V=?

I=2.1A

P=IV

65=(2.1A)V

30.95V=V

R=14.738[tex]\Omega[/tex]

X= number of bulbs

[tex]\epsilon[/tex]= I((1/R)X)^-1

85V= (2.1A)(1/14[tex]\Omega[/tex])X)^-1

(14[tex]\Omega[/tex]/X)(2.1A)=85V

29.4V/X=85V

29.4V=(85V)X

.34588=X

**1. Homework Statement**How many 65-W light bulbs can be connected in parallel across a potential difference of 85V before the total current in the circuit exceeds 2.1 A?

**2. Homework Equations**[tex]\Sigma[/tex]1[tex]/[/tex]Req=1[tex]/R1[/tex]+1[tex]/R2[/tex]+1[tex]/R3[/tex]...

P=IV

V=IR

**3. The Attempt at a Solution**I can't get an answer that makes any sense, but this is what I tried to do.

P=65-W

V=?

I=2.1A

P=IV

65=(2.1A)V

30.95V=V

R=14.738[tex]\Omega[/tex]

X= number of bulbs

[tex]\epsilon[/tex]= I((1/R)X)^-1

85V= (2.1A)(1/14[tex]\Omega[/tex])X)^-1

(14[tex]\Omega[/tex]/X)(2.1A)=85V

29.4V/X=85V

29.4V=(85V)X

.34588=X

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