How much heat in joules is needed to raise the temperature

AI Thread Summary
To calculate the heat needed to raise the temperature of 7.0 L of water from 0°C to 78.0°C, the correct answer is 2.28 x 10^6 J. The calculation involves converting the volume of water to grams, using the specific heat capacity of water, and applying the formula for heat transfer. An initial miscalculation was corrected when the user realized they omitted a factor of ten. The discussion highlights the importance of careful unit conversion and calculation in thermodynamics. Overall, the correct approach confirms the heat required for the specified temperature change.
comoore
Messages
3
Reaction score
1

Homework Statement


How much heat in joules is needed to raise the temperature of 7.0 L of water from 0°C to 78.0°C? (Hint: Recall the original definition of the liter.)

Homework Equations


How much heat in joules is needed to raise the temperature of 7.5 L of water from 0°C to 87.0°C? (Hint: Recall the original definition of the liter.)
2.73e+06 J

The Attempt at a Solution


I answered 2.28^06 J.
I have actually already asked this question on another forum, and they couldn't figure it out either. Please help.
 
Physics news on Phys.org
I think so...

I did 7000 gm x 78 C=546000 calories
546000x4.184j/calorie=2284.5 kj
Then converted kj to j
 
OH. MY. GOSH. I didn't put the 10 in when I answered. The answer is correct. 2.28x10^6 J.
 
  • Like
Likes Greg Bernhardt
comoore said:
7.0 L of water
comoore said:
7.5 L of water
Better turn off the tap.
 
  • Like
Likes Chestermiller and Bystander
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top