How long will it take to boil 1 liter of water?

In summary: It would help to know the conversion rates between watts, joules, and seconds, but in general, you can use the following equation:It would help to know the conversion rates between watts, joules, and seconds, but in general, you can use the following equation: W = J * t
  • #1
EMEE_
11
0
Homework Statement
How long will it take to boil 1 liter of water from 20°C? The heat efficiency / η is 85% , voltage / U 230V and power / P 200W. The answer must be given in seconds.
Relevant Equations
?
Hi.
I have been trying to solve the following problem:How long will it take to boil 1 liter of water from 20°C? The heat efficiency / η is 85% , voltage / U 230V and power / P 200W. The answer must be given in seconds.

So,

t1 = 20°C

t2 = 100°C

Δt = 80°C

V = 1,0 liter → m = 1,0 kg

ηkettle = 85%

U = 230V

P(the power needed to boil water) = 200W

So far I have solved the energy consumed in boiling water: E = c * m * ∆t = 334400_J (joules) Have I used the right formula? And what formulas can I use?

Hopefully, someone here can help me!
 
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  • #2
Are you just supposed to bring it to a boil (begin boiling) or boil it all away?
 
  • #3
I'm just supposed to bring it to a boil.

phyzguy said:
Are you just supposed to bring it to a boil (begin boiling) or boil it all away?
 
  • #4
EMEE_ said:
I'm just supposed to bring it to a boil.
Then your calculation of the energy required looks correct. Do you know how to go from there to the time required? You will need to use the input power and efficiency.
 
  • #5
phyzguy said:
Then your calculation of the energy required looks correct. Do you know how to go from there to the time required? You will need to use the input power and efficiency.

Ok, good if the calculation is correct! :). But I don't actually know how to go from there to the time required...
 
  • #6
Hi EMEE:

Does it help to know that a watt is a joule per second?

Regards,
Buzz
 
  • #7
Buzz Bloom said:
Hi EMEE:

Does it help to know that a watt is a joule per second?

Regards,
Buzz

Yeah, thanks, that might help. But I don't really know what formulas/ equations I should use... Could you please help with those?
 
  • #8
If I'm going 50 miles per hour, and I have 300 miles to travel, how long will it take? If I'm putting in 200 Joules per second, and I need 334400 Joules, how long will it take?
 

FAQ: How long will it take to boil 1 liter of water?

1. What is the boiling point of water?

The boiling point of water is 100 degrees Celsius or 212 degrees Fahrenheit at standard atmospheric pressure.

2. Does the type of container affect the time it takes for water to boil?

Yes, the material and thickness of the container can affect the time it takes for water to boil. Thinner materials and materials with lower heat conductivity will take longer to heat up and reach boiling point.

3. How long does it take to boil 1 liter of water on a stove?

The time it takes to boil 1 liter of water on a stove can vary depending on the power of the stove, the type of pot or pan used, and the starting temperature of the water. Generally, it can take anywhere from 5-10 minutes.

4. Does the altitude affect the boiling point of water?

Yes, the higher the altitude, the lower the atmospheric pressure. This means that water will boil at a lower temperature at higher altitudes. For example, at 5000 ft above sea level, water will boil at approximately 95 degrees Celsius.

5. Can adding salt or other substances to water affect the time it takes to boil?

Yes, adding substances such as salt or sugar to water can increase the boiling point and therefore increase the time it takes to boil. This is because these substances disrupt the formation of water molecules and require more energy to reach boiling point.

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