This guy thinks 1.09g for Model S is suspicious because, um, physics

[BobinBoulder]

Reminds me of an old joke told by my Physics Prof back in college.
===============================================================================
A Physicist and bookie are having a conversation at a horse track
Physicist: I can calculate to 99.9% accuracy who will win the next race, come in second and third!
Bookie: No kidding?!? I'll split half the winnings if you tell me which horses and in what order
Physicist: No problem.

The Physicist scratches a couple of equations onto a racing sheet that all look very complicated and after a few minutes names off the horses and in what order he predicts they will finish.

The bookie rushes off to the nearest loan shark, borrows as much money as he can (promising to pay it all back at the days end or legs and arms will be broken), and runs to the nearest window to bet it all on the trifecta

Bookie gets back trackside and sits down to next to the physicist just as the race starts.

Bookie: Say, I'm no scientist, but can you explain to me how you came up with the winners today?
Physicist: Sure... no problem.... first you assume that the horse is a perfect sphere....
===================================================================================

(and "Yes", I am a (former?) physicist, and I still laugh my butt off every time I hear/tell that joke).

 

[physicsfita]

Reminds me of an old joke told by my Physics Prof back in college.
===============================================================================
A Physicist and bookie are having a conversation at a horse track
Physicist: I can calculate to 99.9% accuracy who will win the next race, come in second and third!
Bookie: No kidding?!? I'll split half the winnings if you tell me which horses and in what order
Physicist: No problem.

The Physicist scratches a couple of equations onto a racing sheet that all look very complicated and after a few minutes names off the horses and in what order he predicts they will finish.

The bookie rushes off to the nearest loan shark, borrows as much money as he can (promising to pay it all back at the days end or legs and arms will be broken), and runs to the nearest window to bet it all on the trifecta

Bookie gets back trackside and sits down to next to the physicist just as the race starts.

Bookie: Say, I'm no scientist, but can you explain to me how you came up with the winners today?
Physicist: Sure... no problem.... first you assume that the horse is a perfect sphere....
===================================================================================

(and "Yes", I am a (former?) physicist, and I still laugh my butt off every time I hear/tell that joke).

The version I learned had the punch line, "First, we assume the cow is spherical and emits milk isotropically." Still cracks me up, too.

 

[BobinBoulder]

The version I learned had the punch line, "First, we assume the cow is spherical and emits milk isotropically." Still cracks me up, too.

Lol... <geek humor is the best!>

 

[787steve]

Thanks a lot!! Snopes takes all the fun out of life. Darn facts.

 

[Stiction]

That is a rather pernicious urban legend. An analysis of how it came to be:

Bumblebees Can't Fly

A more precise and true statement would have been

"Bumblebees can't glide"

 

[icell]

Edmunds has some Model S data. If the P100D tyres are the same these values hold

200 foot diameter skidplate measured at 0.9 G
60-0 stopping 102 feet, equal to 1.13 G average stopping force

I think so.
Any one tested the G force of model s?

 

[icell]

The author is a Prof of Physics -- give him the benefit of the doubt and read what he says.

He is pointing out that high performance cars are likely to reach an acceleration limit based on tyres+roads rather than motive force. One thing I am unsure about though, is whether static friction really is greater than dynamic for this use case. Tyres get hot. He could well be right that take-off is under one G in a stock Tesla on regular roads.

As for actual values, our cars with anti-skid controls provide a fairly simple way to estimate max 0-60: just time how long it takes to go from 60-0 when the brakes are slammed. One G is about 61 meters.

That’s true.
There is another reason why the g of drag racing car is higher, see the pic:

Slow motion from

The surface between the tyre and road is quite large. And actually the road is rubber surface, not asphalt anymore.
The friction of rubber to rubber, any one know how much it is?

 

[icell]

Actually a car could get more than 1.1g when breaking, so the limit of the same tyre and road could be 2.5sec from 0-100km/h.

 

[Shock-On-T]

No, the strangeness of quantum mechanics only applies at the quantum scale.
There is no uncertainty at all once you get to the macro scale. The physical world at this scale is completely and perfectly described by Newtonian physics (refined by Einstein).
Faith seems to be an artifact of psychology. Show me a human and I'll show you a deity, be it Zeus or Ra or whatever you kids are praying to these days...