Join the Car Talk Community!

Electrical Circuit

The Puzzler

RAY: Now you'll notice I didn't mention how much wire was inside the starter motor.

TOM: Like it almost doesn't matter.

RAY: Right. It doesn't matter. Let's say you say 10 feet over 5,280 feet. That's 1/500th of a mile. Right? And electricity travels at 186,000 miles per second, using the formula distance equals rate times... you could figure it out right? A simple calculation that any moron could do.

TOM: And many did.

RAY: Did you do it?

TOM: Yea. I even used my slide rule. I got slide rule accuracy with it.

RAY: And you'd come up with some answer.

TOM: I got a number and I didn't know where to put the decimal point. But I know what the answer is.

RAY: But the answer, amazingly is, about 4 hours.

TOM: Oh. Come on!

RAY: Because electricity is indeed the flow of electrons. Most electrons are bumping into other ones and pushing stuff around. It's sort of like having billiard balls in the air. What's happening is the energy is flowing through the wire, but the electrons, an individual electron, takes a long time because it is bumping into what?

TOM: Other electrons.

RAY: And atoms in the wires. So that's the answer.

TOM: How does one get four hours?

RAY: According to this brilliant electrical engineer. Whose name he wrote with invisible ink.

TOM: This is the most bogus puzzler.

RAY: I have a better one for this week.

TOM: I hope so.

[ Car Talk Puzzler ]

Support for Car Talk is provided by:

Donate Your Car,
Support Your NPR Station

...and get a tax break!

Get Started

Find a Mechanic



Rocket Fuel