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28 views

### Warm or cold air

Which air can be used to dry out food or clothes? Warm or cold air? I've read that keeping food in the fridge makes it dry out. Blowing hot air to the hair also dries the hair out. I'm confused.
24 views

### The Refractive Index of Water after Several Heating and Cooling Cycles

If the refractive index of water under a certain temperature, say 20 degreeC, is 1.33334. Will it return to exact the same value after one or several heating and cooling cycles? Or will it shift a ...
44 views

### How long does it take to cool down a drink with ice?

If I have a bottle or container with X fluid ounces of water at temperature Y (say, fridge temperature or room temperature), and I put ice or ice sticks (composed of water) in it that make up Z fluid ...
46 views

### How does an ultrasonic humidifier / atomizer affect temperature?

Evaporative cooling is a technique used to cool air by using the evaporation of a liquid. My google research on evaporative cooling shows a ubiquitous concept of forcing air through a pad/membrane/...
1k views

### Does tea made with boiling water cool faster than tea made with boiled (but still hot) water?

I always make tea with boiling water - not water that is almost boiling, not water that has boiled and stopped boiling a few seconds earlier - in my opinion, for the best tea flavour the water must be ...
87 views

### How many calories of energy does it take to heat up 1 cubic inch of water 1 degree Fahrenheit? [closed]

In metric, one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade--which is 1 percent of the difference between ...
72 views

### Is the triple point of water exactly 0.01 $\deg$C?

Is the triple point of water exactly $0.01 \deg$C, or is this an empirical value/is there some uncertainty to it? If so, how do we know it is exact, and why?
106 views

### Which one is better to boil water, using high heat or less heat?

Consider that I have a water boiling kettle as below. Assume that it is made of metal, not plastic (but plastic probably also will do). Assuming I can adjust the power it uses to boil the water with ...
60 views

### water pipes break when temperature goes down, how to estimate the energy involved?

Normally low temperature is associated with lower energy state and high temperature with higher energy state. There is an apparent paradox when a water pipe breaks due to low temperature: when ...
97 views

### In thermal spas the temperature of steam is about $50^{\circ}C$, but feels way hotter. Why?

So when you're in hot water and start to move or something the steam feels really hot even though I read its temperature is about 50 degrees Celsius in thermal spas. So why does it feel that warm?
62 views

### why does cold water have Translucent visibility? [closed]

If ice is to formed soon, why ice Does not have Tranparent vision.
3k views

### At what pressure will water boil at room temperature and why?

Is there a specific pressure that is needed to boil water at room temperature? If there is, what is it? Why does water boil at a low pressure at all?
43 views

### When we mix water with H$_2$SiF$_6$ and boil them, how much of the H$_2$SiF$_6$ evaporates?

If water evaporates also at temperatures much lower then its boiling point, and so do, I believe, other liquids, how much H$_2$SiF$_6$ (boiling temp. 108 C) is to be found in the steam over boiling ...
447 views

### Final temperature of ice and water [closed]

My answer doesn't seem likely but I can't see where I've gone wrong: Q: Ice of mass 0.125kg at -5 degrees is added to water of mass 0.25kg at 8 degrees. Calculate the final temperature of the water ...
1k views

### Why can I touch hot things longer with water on hands?

So I have done a couple of personal experiments with water on my hands. One day I was taking bread (rolls to be exact) out of the oven with my bare hands and burned my hands when my hands were dry. ...
94 views

### Determining friction force while stirring water

So I researched a bit on this, and found a video which showed an experiment in which he boiled the water, just by pouring it into a high-speed blender and stirring it. Can someone tell me how can I ...
20k views

### Why does water stop boiling immediately after turning off the heat?

When I am heating water on a gas stove, it begins to boil after some time and bubbles of air can be seen escaping out. However, as soon as I increase the amount of heat in the stove, the rate of ...
196 views

### Is it possible to prevent water from cooling by keeping it in an rigid container?

If you fill a soft plastic water bottle with hot water, close the lid, then cool the water down, the bottle will contract. When you open it up, it will expand again. Conversely, if you used a hard ...
172 views

### How do I calculate how long water will take to warm from 22°C to 35°C?

I'm a microbiologist and my physics is not up to par for figuring this out. I've requested our engineering department to perform a temperature mapping of the vessel, but they can't do it for me. I ...
50 views

### What is the equation relating the mass of water and its temperature change in a fixed time?

I heated up a beaker of water to 70˚C and set a time of 2 minutes. I measured the change in temperature in that time interval. I changed the mass of water and measured the change in temperature each ...
150 views

### Water molecules on the Sun? How does that work?

I've been reading about water on the Sun. The water they talk about is supposedly in a gaseous state because the Sun is so hot. But I'm wondering how even that could exist. Wouldn't the extreme ...
528 views

### Boiling potatoes

If the temperature of boiling water is about 100 ºC (depending on air pressure), why are boiled potatoes on a high stove flame cooked faster? From the English Wikipedia: Acrylamide was discovered ...
3k views

### Does salt affect the boiling time of water?

If I have 1 cup of water on the stove and another cup of water with a teaspoon of salt. would the salt change the boiling time of the water?
442 views

### Why is steam-cooking slower at higher altitudes, where water boils at a lower temperature?

This question comes from a chemistry test that i got back. I'm posting this on physics.stackexchange because i feel that i don't get the physics side of it. We learned that temperature increases the ...
97 views

### Must gaseous water be 100C (or greater) regardless of pressure?

I know that if you evaporate a molecule of water, that it must be 100C in order to be gaseous, so that it will take that heat with it if it wasn't already that temperature. This has a cooling effect ...
15k views

### Water pressure vs temperature

If I have a sealed enclosure full of water (constant volume) at 25˚C at atmospheric pressure, I then heat the water to 50˚C. Would the pressure in the sealed enclosure change? If the pressure has ...
137 views

### How warm are rain drops?

I thought of this question after a week of jogging, where each day after it rained, the temperature seemed warmer. I also noted this as a lifeguard where, after closing the pool due to thunder, we ...
60 views

### Water not turning into ice until brought into warmer temperature

I left a water bottle in the freezer for it to cool since it was warm, so I could drink it sooner. After a couple hours I forgot I put it in there, so I opened the freezer, and to my surprise it was ...
65 views

### Fully understanding the effects of specific heat

I have yet to find a source that adequately explains our reasoning behind why we describe something as "hot" and something as "cold". Textbooks describe the water as something that is less hot than ...
276 views

### Water dripping from handheld shower head loop

I've got a shower head attached to the wall by a long metal covered flexible hose. The shower head stays attached to the wall so there is a long loop of hose hanging down between the wall and the ...
63 views

### Does pure water freeze at the same temperature even if there are a mix of gases in the environment?

For example water has a triple point at 670 Pa c.ca.at 0.01°C Could she freeze at this temperature even if there is another gas in the mixture of the vapour,for example He4 at 1Atm? Does the Rault law ...
1k views

### What is the temperature of water vapour itself?

Assuming standard atmospheric pressure, Does the water vapour created from boiling water have the temp of 100 °C? What about water vapour created by evaporation at room temperature?
229 views

### Why does drying off with a towel at room temperature not feel cold?

I thought that if you're wet, a breeze will feel cold because the water moisture is evaporating and whisking away heat along with it. With a towel at room temperature (same temperature as a breeze), ...
611 views

### Boiling of Water

I studied in textbooks that the boiling point of water is the temperature at which the vapor pressure is equal to the atmospheric presssure. My doubt is since the vapor mixes with atmosphere, how can ...
How does the relative humidity of the air affect the speed at which water evaporates? I know there are other parameters that affect it, so I made this assumptions: We have a plain metal plate of $1m^... 1answer 229 views ### Specific heat capacity vs KE gain of particles To increase the temperature of 1kg of water by 1C you need 4200J of energy. However, the KE gain is only$\frac{3}{2} k_B \Delta T \cdot 6.02\cdot 10^{23} \cdot \frac{1000}{18} = 692.3$J. Where does ... 1answer 29 views ### How to construct a more efficient cooler made by cheap materials to cool a glass bottle containing hot water without pouring the water out? details -limitations:it can only use five blocks of ice and the cooler must consist one container to put the glass bottle.Also,cannot interfere the water in the glass bottle such as to stir it. but ... 3answers 1k views ### Is the boiling point of water really 100°C? If so, how come water evaporates at lower temperatures? [duplicate] I had this doubt since so many years. Suppose you pour water on the floor. Then you switch on the ceiling fan and select stage 5 on its regulator. Then the water on the floor evaporates without ... 4answers 4k views ### Temperature of steam rising off boiling water When boiling water on a stove, will the temperature of the steam vary significantly with the temperature of the burner? Person A's argument: So, once individual water molecules reach 100C/212F, they ... 3answers 822 views ### Can water vaporize without reaching 100 degrees celsius? [duplicate] I think many of you just let water sit somewhere outside, on a surface it can not be absorbed in. What happened to the water? Did it vaporize? Can water still vaporize if it is not on 100 degrees ... 2answers 6k views ### Why does a wet towel become more hot than a dry one? I remember a long time ago my mum had told me not to use a wet tea towel when taking food out of the oven because you can burn your hands - lo and behold, it came time to make dinner and I did not ... 1answer 122 views ### what will the buckets water temperature? [closed] Suppose there are 2 buckets.. say Bucket A and Bucket B. Both contains 20 liters of water and both are at same temperature. A person took 2 liters of water from A and 4 liters from B. He boils both ... 1answer 414 views ### Finding atmospheric pressure using temperature of boiling water I was checking the temperature inside my oven using a multimeter with a temperature probe. I had set the oven's thermostat to 190o C, and it had reached equilibrium, but the measured temperature was ... 3answers 1k views ### Why does blowing air over hot wet surface makes it dry faster? After removing the boiled water from a hot kettle, which is wet, the water evaporates rapidly if air is blown over it. What is the science behind this phenomenon? 1answer 871 views ### Freeze water in red-hot container While reading Edgar Allan Poe's short story The thousand-and-second tale of Scheherazade (about a fantastic journey to the present of 1850) I once stumbled on the following footnote to the phrase "... 0answers 1k views ### Why water heat capacity has minimum at body temperature? Water heat capacity has the following plot: One can see it has minimum near 40 degrees of Celsius, i.e. close to human body and other warm blooded animals have. Is this just coincidence? UPDATE ... 2answers 1k views ### Do foods with water exceed 100° celsius in the oven? I was thinking that water in liquid state can't normally be much above 100 degrees celsius because it boils, so probably foods with lots of water like vegetables don't warm more than 100 degrees. Does ... 2answers 2k views ### How can I boil water at a temperature less than 100 degree Celcius? I need to boil a water-based solution at a temperature lower than 100C. What kind of liquid should i add to the water to make this happen? 1answer 333 views ### How does my car antifreeze work (in thermodynamic terms)? Freezing point depression Water freezes at 0$^{\circ}$C, ethylene glycol freezes at -12$^{\circ}$C, but my car starts at -20$^{\circ}$C. Mixing them together prevents my car engine's coolant from freezing down to -30$^{\...
Water expands at temperatures over $5^\circ\mathrm C$ strictly monotonic. If you now drink $1~\mathrm{L}$ water ($5^\circ\mathrm C$) which will expand in your body on $37^\circ\mathrm C$, did you ...