Why might an icy road at -1 celcius be more dangerous than a road at -10 degrees celcius?
336057
When the tyre goes over ice it actually adds heat to the ice due to friction of the tyres on the road. Therefore when you are moving over -1 degree celcius road then you actually heat the ice into water. Because it is water you will not actually be on a solid surface and will move more freely.\n\nAt -10 degree celcius the car friction may not melt the ice very well and so the surface becomes more solid. Because it is  more solid then your friction is better and you are less likely to slip... however dont brake or accelerate quickly or the friction temperature will increase and you get similar reaction to above.
672239
because extreme heat is better than cold.
278799
It's a figurative language because it's not actually 100 degrees below zero, just cold enough that you'll be nippy if you go out.
150789
I think yes, definately! I work on Alaska's North Slope and I know that sound absolutely travels better at extremely cold temperatures. When it is minus 40 or 50 F you can hear vehicles coming from a much greater distance for example. Can't say why exactly. Maybe because the molecules in the air are closer together (condensed) and therefore transmit sound more efficiently (like water).
825154
Sleet is a mix of water and snow.  Freezing rain is more interesting.  Usually water freezes at 0 degrees Celsius.  But if it's completely free of bubbles and dust particles that ice crystals can start to form on, like in the upper atmosphere, it can cool down to minus 40 Celsius before it freezes.   This is supercooled water.  The moment supercooled water hits a solid object, like the ground or an aeroplane wing, it freezes.  Freezing rain is supercooled water, and it's very dangerous to aircraft.
403258
Igloos inside are warmer than the outside, but this doesn't mean they are above 32ºF.  Since there is no wind inside, heat from the bodies is kept longer (there is little convection) and this creates a samll micro atmosphere inside the igloo. If the air inside goes above 32º, a small layer of ice from the walls can melt, this reduces the temperature close to the walls and again a layer of ice is formed giving back a bit of the internal heat lost during melting.
25339
Air temperature may be several degrees warmer than ice surface temperature. Light, including infrared or warmth, is reflected from white surfaces.\n\nThe surface of the ice will melt, slowly, during the day, but it will freeze again over night. That's one of the reasons why a snow field slowly turns into ice.
283245
yes, it is. ice is hard and brittle. this in itself is enough to chip or crack teeth. fillings and teeth are further adversely affected by the expansion and contraction that occurs with the sudden temperature change. the extremes in temperature may affect nerve endings in already sensitive teeth and lead to extreme discomfort.
220158
Do not offer bribes, this is immoral.\nMany here come to assist as a service.\n\nYour answer is here:\n\nWhen ice melts, kinetic energy of H2O molecules is increased by absorption of heat energy from the surroundings.\n\nHowever as the kinetic energy is increased to make the molecules move freely, Hydrogen Bonding among the water molecules becomes more effective and so a particular intermolecular distance is maintained among the molecules. \n\nThis is effective upto 4C.\n\nAfter 4C the H-bonding becomes so week as against kinetic energy that free movement of molecules is no more restricted and thus abnormal behaviour of water molecules is stopped.
781935
because it is very cold at cloud level and at cloud level that\nrain was once snow until it reached below a certain level and\nthen it melted.
895765
Temperature must get below 32 degrees Fahrenheit or 0 degrees Celsius.\n\nWhen it gets that cold, the H2O particles have more resistance moving around until they move around less and less until water freezes. The particles are still moving... just very slowly. The particles also get larger in this process; thus the reason why ice expands.
291269
Cold water has more dissolved gases in it than hot water.  Any dissolved solutes cause the freezing point of water to be lower than pure water with nothing dissolved in it.\n\nThis means if your power goes out in the wintertime and it is about 32 degrees F outside, the water in your hot water pipes is more likely to freeze than the water in your cold water pipes.  This is because the freezing point of the water in your hot water pipes is higher than the freezing point of the water in your cold water pipes.\n\nSpeed isn't being considered here.  The cooling process is assumed to be slow so that the pipes are in thermal equilibrium with surroundings.\n\nAlso check out this link.  It is from the Alaska Science Forum.  They can explain the water pipes problem more correctly than me and they have more personal experience with the phenomenon.\nhttp://www.gi.alaska.edu/ScienceForum/ASF4/440.html
216514
That all depends on the altitude. At 1 atmosphere of pressure (sea-level), the melting point is 32F and 0C. At higher pressures, this temperature lowers. This is why ice skating works. The pressure of the blade causes the ice to melt, letting the skate glide.
85617
Beats the heck out of me.  I found 39:4-97.2 at:\n\nhttp://www.state.nj.us/mvc/cit_violations/d_vp_pnf.html#NJSA\n\nBut that talks about being unsafe when you drive.  I couldn't find anything directly on point about ice and/or snow.\n\nSome lawyer wants you to know this:\n\nhttp://www.njlaws.com/unsafe_driving.htm\n\nHope it helps, don't feel like I did much good here.
535872
You should show how ice expands and can damage roads and concrete... very stiff materials.\nCheck out the links\n\nOh yes and don't forget about wear and tear cars and other vehicles can cause... I am not sure how much time you have for your science fair project... typical road wear studies can last for years.
172797
there is ice when it is cold, this is known as being frozen
35421
Ice will form on a surface that has water on it, if the surface is below freezing, or technically, can extract enough heat from the water to allow the water to fall to below freezing temperature.\n\nThis happens a lot when it has snowed, then there is a sunny or warm day, melting the snow to water because the ground temperature warms to above freezing.\n\nThen, at night, the ground will maintain the above freezing temperature for a while, but slowly cool off.\n\nA bridge has less 'mass' to maintain the warmer, higher, temperature, plus the air flowing above and below the bridge will cool the bridge faster, so it cools to below freezing faster. This causes bridges to frequently form ice more quickly than ground surfaces.\n\nUnder the right circumstances, the ice will form on the road as well. Just ask a busy auto body shop in winter.