View Full Version : Interesting Physics on Car Talk

2002-Mar-30, 03:28 PM
Just listened to Car Talk this morning...let's see how much of the converstaion I can recreate here.

The caller was asking what the best course of action would be in an unvavoidable head on collision between a semi and a small car (from the perspective of the small car!) Should he speed up or slow down.

The joke answer was that you speed up until you are going close to the speed of light and the car's mass will increase until it is much more massive than the truck. They then said that "In order to get to the speed of light, you would have to go faster than the speed of light." Sounds like they are confusing velocity and acceleration again (the acceleration would have to be huge, but the velocity would never be greater than that of light).

Okay, so I don't expect great science on Car Talk /phpBB/images/smiles/icon_smile.gif


2002-Mar-30, 04:45 PM
I hauled on over to the Cartalk website (http://cartalk.cars.com/Radio/Show/) to listen to it, but it seems that they don't have the program up yet--Segment One is "You Can Learn A Lot by the Age of Six…" That's not the one, right?

2002-Mar-30, 05:39 PM
It was just on a couple of hours ago. Try late today or tomorrow. I can't remember if it was late in the second half of the show or early in the third half (hey, they aren't too good with fractions, either!)


2002-Mar-30, 11:09 PM
Maybe they meant half-hours?

Donnie B.
2002-Mar-30, 11:15 PM
No, they meant fractions... Tom and Ray like to get cute with things like that. Just check out their mythical staff members. Their lawyer is Hugh Louis Dewey of Dewey, Cheatem, and Howe.

Kaptain K
2002-Mar-31, 10:01 AM
Or their "statistician" Les Ismore. /phpBB/images/smiles/icon_biggrin.gif

2002-Mar-31, 01:38 PM
Still hasn't changed, as of today.

But I did find this: Speed of Light and Dark (http://www.cartalk.cars.com/Radio/Back-Tracks/).

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<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-03-31 08:39 ]</font>

2002-Apr-01, 04:47 PM
I heard this show too. I'm quite sure they were going for the laugh line rather than technical accuracy. /phpBB/images/smiles/icon_biggrin.gif All things considered, they go for the laugh line rather than accuracy no matter what is going on. /phpBB/images/smiles/icon_lol.gif

Good ol' Tom & Ray. The one truly funny thing on the radio. They'll screw up anything for a laugh. It's well worth the trip to their web site at cartalk.com just to read the fictious list of people associated with the show. Their body work expert is Denton Fender. /phpBB/images/smiles/icon_smile.gif

2002-Apr-01, 08:21 PM
All right, they posted it. Listen to segment #9.


I know they go for the joke rather than correct physics, but it is still fun to break down silly physics sometimes /phpBB/images/smiles/icon_smile.gif


2002-Apr-01, 11:02 PM
O wow. It had to be Bob from Babylon. That got em started.

The boys did indeed get confused about acceleration and speed, I think. But they did come up with a good answer--if the driver can change speed enough, might as well go backwards!

2002-Apr-02, 03:04 AM
But they also made a reference to going slower decreasing energy and if you go backwards, better. Going backwards does not decrease energy. KE = .5mv^2, well a negative squared is still positive. Momentum changes sign, however.

Love those crazy Car Talk guys /phpBB/images/smiles/icon_smile.gif


2002-Apr-02, 12:03 PM
Hard to hear with all the laughing and snorting, but I think the gist of it is that a deceleration (even to the point of going backwards) is going to reduce the amount of energy dissipated in the crash between the car and truck. I think that is a reasonable interpretation.

ObAstronomy: I wonder when they're going to get a chance to test drive the shuttle?