science thread

[chrisd]

this is the thread for science q and a. Any questions about physics, philosophy etc. can be posted here and hopefully answered by skilled members of the b-community! Here goes:

Isn't it true that a car on a wet road travels faster than a car on a dry road moving with the same speed.
How come? Isn't the plus in terms of less friction cancelled out by a minus in less tire tread (which is needed to move)?

[Sarky Devotchka]

I'd think that a dry road would be faster because there's more grip. although, I suppose a certain amount of water may act "sticky" depending on the type of tires. THERE ARE TOO MANY VARIABLES.

[Sarky Devotchka]

hang on now, if they're moving at the same speed, one cannot be going faster.

is this a trick?

[sab0tage]

A science lecturer at college once told us that if you were following a truck carrying hay/straw and a piece of straw flew off and hit your windscreen at the correct speed/angle etc it could pass straight through.

[ms.peachy]

hang on now, if they're moving at the same speed, one cannot be going faster.

Ayuh.

I think what the OP means is, is it true that it takes less applied energy to move a car on a wet road at the same speed as on a dry one.

[Sarky Devotchka]

A science lecturer at college once told us that if you were following a truck carrying hay/straw and a piece of straw flew off and hit your windscreen at the correct speed/angle etc it could pass straight through.

that would never happen. the density of the glass would provide enough force to bump the straw in a different direction. not even considering the fact that the straw would be losing force the entire time, having just been moving in the same direction and speed as the truck ahead of you...it's not like it was projected at your windshield. You'd all have to be going very fucking fast.

[sab0tage]

But in theory - if high speed wasn't an issue??

[ms.peachy]

But in theory - if high speed wasn't an issue??
It could never not be an issue, because velocity will always be a factor in the equation.

[sab0tage]

so he was lying to us all!!!

[Sarky Devotchka]

if the initial velocity is zero on a wet road and a dry road, the car on the dry road would probably get going faster because there's more surface friction for the tires to push off of. the water would cause some slipping before the tire actually gripped the road. that coupled with the fact that roads have a certain amount of oil that would mix with the water and create even more slip.

I'm sure there are more scientific words I could be using, but meh.

[sab0tage]

if the initial velocity is zero on a wet road and a dry road, the car on the dry road would probably get going faster because there's more surface friction for the tires to push off of. the water would cause some slipping before the tire actually gripped the road. that coupled with the fact that roads have a certain amount of oil that would mix with the water and create even more slip.

I'm sure there are more scientific words I could be using, but meh.

to be less scientific, cars wheelspin better in the wet!!

[Sarky Devotchka]

oh sorry, I was thinking about the first question again.

the straw thing, yeah, I don't think that could ever happen. think about when rocks hit your car, it's because the tires in front of you flipped the rock back in an opposite direction towards your windshield with more force than a piece of straw floating off of a truck would.

I'm curious about what your teacher meant. maybe if it happened in a vacuum?

[Sarky Devotchka]

to be less scientific, cars wheelspin better in the wet!!

no!

[sab0tage]

oh sorry, I was thinking about the first question again.

the straw thing, yeah, I don't think that could ever happen. think about when rocks hit your car, it's because the tires in front of you flipped the rock back in an opposite direction towards your windshield with more force than a piece of straw floating off of a truck would.

I'm curious about what your teacher meant. maybe if it happened in a vacuum?

I really can't remember. All things said he was by far the best lecturer at college though

[Sarky Devotchka]

I was thinking hydroplaning, but I dunno. I mean...Science is all new to me, right. I used to think a fake guy died on a cross so that we would be saved from ourselves. This shit kept me from science.

What the fuck am I going on about...? Honestly...

hydroplaning is floating on top of the water, so there's no grip, it's just rubber sliding over water using the velocity acheived previously when the tires touched the ground.

I could be making all of this up.

[jabumbo]

i love physics



but i hate chemistry

[cosmo105]

the straw just doesn't have enough mass to do any damage. aside from scraping off the odd micron here or there, really.


yeah, fuck chemistry. i have it in an hour and a half.

[jabumbo]

the straw just doesn't have enough mass to do any damage. aside from scraping off the odd micron here or there, really.

lots of mass isn't needed to do the damage...

[Sarky Devotchka]

if you shot a piece of straw out of a gun into your butt, that would hurt a lot. IT'S A SCIENTIFIC FACT!

[Mr. Boomin'Granny]

lots of mass isn't needed to do the damage...
but the velocity that you and the truck would need to be at is outrageous.

Yes it is possible, feasible no.

[kleptomaniac]

i'll need to save this thread. since i don't have physics 'till next year. (lb)

[alexandra]

i love physics



but i hate chemistry
vice versa here.

[voltanapricot]

vice versa here.
mmm yah, I really never was a physics gal, it's like maths to me and I'm rubbish at maths.

[alexandra]

same here.

plus you get to sniff fabulous acids in chem class.

[Friis gal]

The only thing I can remember from physics/chemistry is how to get wine into pure alcohol, but don't drink it! You never know what have been in the glass you made it in, and therefore it tastes awful...

[chrisd]

i have another question: Do you guys really believe in Darwinism? My critique isn't creationist or anything, it's more that i sometimes wonder if genetic changes to a species also occur during the life of one of it's specimens. Like; haven't you ever noticed that people who are around one another for long periods of time like classmates or office mates look alike not just fashionwise, but also physiognomically?

[HEIRESS]

I hate having to retype my evolution/darwinism rant everytime the topic comes up again

lemme go see if a copy is still kicking around this bitch somewhere....