Question about solving for resistance

[Blossom'sGirl]

This is a question copied directly out of the CPO Physical Science book using ohm's law I=V/R I get .75 ohms not 3 ohms. Am I missing something. (I hate studying electricity, that is why I went into mechanical engineering)

 

 

b. A motor in a toy car needs 2 amps of current to work properly. If the car runs on four 1.5-volt batteries, what is the motor’s

resistance? Answer: 3 ohms

 

You can look at the book here: We are in the Physical science book, Unit 4, p.200

 

http://alms.hermiston.k12.or.us/science-text-books

[Bambam]

This is a question copied directly out of the CPO Physical Science book using ohm's law I=V/R I get .75 ohms not 3 ohms. Am I missing something. (I hate studying electricity' date=' that is why I went into mechanical engineering)

 

 

b. A motor in a toy car needs 2 amps of current to work properly. If the car runs on four 1.5-volt batteries, what is the motor’s

resistance? Answer: 3 ohms

 

[/quote']

 

I = 2 amps

V = 1.5 + 1.5 + 1.5 + 1.5 (four 1.5 V batteries in series, right?)

I= V / R 2 = 6 / R

R = 3 ohms

 

I never enjoyed the mechanical engineering classes I had to take which is why I majored in Electrical Engineering!

[Blossom'sGirl]

Oh duh! I totally missed the four batteries. That's what I get for trying to multi-task during science class. I guess I have to remember that when I get on the kids' cases for not reading the problem carefully.

 

Thanks!