How long does it take for ice to melt at average room temperature?
This depends on several factors:The temperature of the ice (it could be well below 0 degrees C)The mass, shape, and volume of the iceHow much room-temperature air is available to transfer heat into the iceThe rate at which the room-temperature air is able to transfer heat into the ice (depends on surface area of contact, ventilation)An extremely cold (perhaps -40 degrees C) spherical ball of solid ice about 1 meter across, if placed into an unventilated very small room at room temperature (about 20 degrees C), will take a very, very long time to melt. It could last several days, perhaps even up to a week. If the room is tiny enough, the ball of ice will chill the air in the room, so that it’s no longer at room temperature. (It will, effectively, turn the room into a large ice-box refrigerator.) If the room is very, very large (like a gymnasium with full-size basketball court and bleachers), then it won’t cool down noticeably, and the ball will melt faster, but may still last a few days to several days.If, however, the same mass of ice is already very near the melting point (perhaps -1 degrees C), and instead of being physically configured as a compact sphere, it’s configured as a large number of very thin sheets (each sheet being 10 meters by 10 meters by 2 millimeters thick), and ventilation fans are used to blow room-temperature gymnasium air over and between these sheets of ice, they will melt very, very quickly — perhaps being completely melted in less than an hour or as little as 20 or 30 minutes. The very high surface area, combined with the movement of air (for efficient heat transfer from the air to the ice), greatly accelerates the melting. Starting the ice at -1 degrees C instead of at -40 degrees C also gives it a head-start for melting.
If air temperature is 102 degrees what is temp on cement. and pavement?
Hard to say for sure as it is not necessarily related to the air temperature. The composition of the surface and how much exposure to the Sun it has will affect it's surface temperature.
If all the roofs and cement areas we cover on the planet were painted white, how much would that effect the earth’s albedo to cool the planet?
Here’re some interesting facts about how it would help.Earth’s albedo (reflectivity index) is 0.29. That means 29% of the rays would get reflected from the Earth. [1]Cities, made of concrete reduces this index to 0.1, or 10% [1]3% of total surface area is covered by houses on the Earth. [2]So, if you paint all the rooftops white; you can increase the index from 0.29 to 0.3. This increase will (over the period of a century) will decrease the temperature of the Earth by 1 degree centigrade. [3]Just 1 degree? That’s not worth it right? But, remember! The global temperature has just increased by 0.8 C since the year 1880. [4]What can decrease in 1 degree do?Save up to 15% of iceberg meltdown on the poles. [5]Can increase 5–15% of crops [5]Can reduce wildfires by 200–400% [5]Wal-mart has some 4368 malls in United States; out of which 3021 rooftops are painted white. More reflectivity; less cost of cooling system. [6]Cool, right?Sources:[1] Measuring Earth’s Albedo[2] Marc Perez's answer to What percentage of Earth's land is used for infrastructure like roads, buildings, all pavement, etc.?[3] Painting roofs white is as green as taking cars off the roads for 50[4] Global Temperatures[5] http://dels.nas.edu/resources/st...[6] White Roofs Catch On as Energy Cost CuttersFollow my Quora blog: Mysterious Planet: The Earth for more stuff like this.
What should I expect when moving to Phoenix?
Heat.Probably the biggest difference I noticed, I also worked construction at the time, was the heat of day and night in the summer. If you originate in a northern state, your activities will reverse - Do stuff outside in the winter and stay inside during the summer (or go north).Opposite to what you think... long sleeves and pants will protect you from over exposure to the sun. Shorts and no shirt/less shirt can get you sick in a hurry. NEVER dump cold water over your head or expect to wake up on the ground.Personal bubbles are bigger.People tend to stay to themselves for the most part. I come from a fairly small town in which most people you walk past say hi or see you working on your car in the parking lot will come by to offer help. I found this to be almost nonexistent in Phoenix. People are friendly, just first encounters can be a bit standoffish - why are you talking to me mentality.Car insurance.You will have to buy uninsured driver protection. A lot of hit and run issues with illegals has caused this to be required. Expect a higher premium on your car insurance there when considering the cost of living there. Call your insurance company and ask them to provide an estimate.Monsoons.You think it pours down rain in your town... just wait. When you get to Phoenix, notice the storm drains at the intersections. Those six foot long holes in the pavement are no joke. Water from rains can often fill a complete lane in a road.Flash floods are part of the monsoons as well. Deserts don't soak up water like you would think so most of it runs off.Sports and barsLots of sports here so if you like sports you have a full range - even pre-season stuff happens here. You have baseball, basketball, and hockey as professional sports.Lots of bars all over town. Scottsdale for the uptown types (cover charges and dress requirements. But a lot of great variety and plenty to do.Avenues and StreetsAvenues = everyone else --- Streets = high-end, high price. Everything west of Central is avenues while east is streets (towards Scottsdale).But a nice thing is the city is on a grid. You give me a street name and an address and I can drive straight to it. They did a great job with city layouts and traffic flow.Indian School road will throw you for a loop when you get used to the grid layout because it goes at an angle. You'll know what I'm talking about if you drive it.Just a few I can rattle off my head quickly...