Amount of watts needed to heat water

  • Thread starter Thread starter wakejosh
  • Start date Start date
  • Tags Tags
    Heat Water Watts
AI Thread Summary
To determine the power needed to heat water, it's essential to understand the relationship between calories and watts. A calorie is a unit of energy, while a watt measures power, which is energy per unit time. The conversion is approximately 0.239 calories per watt, but it's crucial to track units carefully to avoid confusion between seconds and hours. The small calorie (gram) definition should be used for accurate calculations. Understanding these conversions will help in calculating the required watts to heat the water effectively.
wakejosh
Messages
101
Reaction score
0
I have a problem where I have a cup of water and I have to find out how much power I need to generate to heat it by a certian amount. I can't seem to find the equation I need in my book, can someone help me out? thanks.
 
Physics news on Phys.org
ok., now I am just trying to figure out how many watts = a calorie. is it 0.239 calories = 1 watt?
 
Keep in mind that a calorie is a unit of energy, and a watt is a unit of power. Do you know how to convert from power to energy? (hint -- keep track of your units so you don't mix seconds and hours, etc.)
 
i don't know, how do i convert watts to calories?
 
wakejosh said:
i don't know, how do i convert watts to calories?

It says how right at the top of the wikipedia page that I posted a link to. Use the small calorie (gram) definition.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Mixing water and ice
Replies
12
Views
866
I try to solve a thermodynamics problem on heat transfer
Replies
3
Views
2K
How much ice to cool down this water?
Replies
17
Views
5K
Do you need to account for the water heating up to the boiling point?
Replies
23
Views
2K
How much time does it take to warm up water?
Replies
15
Views
2K
How do we obtain an ampere-hour rating given voltage and watt-hour?
Replies
4
Views
1K
Thermodynamics - Latent Heat Problem (finding mass)
Replies
7
Views
2K
Calorimetry - finding the final temperature of a system of ice and water
Replies
7
Views
2K
Cylinder in a heat bath @ 0C contains water and ice & is compressed
Replies
19
Views
2K
I understanding a concept about motor efficiency
Replies
11
Views
2K

Hot Threads

Recent Insights

Back
Top