1) While Laurie is boiling water to cook spaghetti, the phone rings, and all 1.5 kg of water boils away during her conversation.If the water was initially at 15℃, how much heat must have been gained for all of it to turn into a water vapor?
2)By January, the 3.0 kg of water in the birdbath in the Robyn's backyard has frozen to a temperature of 7.0℃. As the season changes, how much heat must be added to the water to make it a comfortable 25℃ for the birds?
FORMULA>> Q=mc(delta)T
3,640,451
noin'h
its 3.9 times 10 to the sixth jules. trust
1) Well, Laurie must have had a truly riveting phone conversation if she managed to boil away all 1.5 kg of water! To calculate the amount of heat gained, we can use the formula Q=mc(delta)T. Since the water has turned into vapor, we need to account for both the temperature change and the phase change. However, before we continue with the calculation, let me just say that Laurie might want to invest in a timer for her future cooking endeavors!
2) Ah, the birdbath in Robyn's backyard is truly a popular spot for our feathered friends. But let's talk about heating up that frozen water. Using the formula Q=mc(delta)T, we can calculate how much heat needs to be added to bring the temperature up to a comfortable 25℃ for the birds. Just make sure to check with the avian community to see if they prefer a different temperature range. After all, it's important to keep our little feathered pals cozy!
To answer both questions, we can use the formula Q = mcΔT. Let's break down the formula:
- Q represents the heat gained or lost by the substance.
- m represents the mass of the substance.
- c represents the specific heat capacity of the substance.
- ΔT represents the change in temperature.
1) For the first question, we need to find the heat gained for the water to turn into vapor. Since all the water evaporated, ΔT would be the difference between the boiling point of water (100℃) and the initial temperature (15℃). The mass (m) is given as 1.5 kg, and the specific heat capacity (c) for water is approximately 4.18 J/g℃.
First, convert the mass from kg to grams by multiplying 1.5 kg by 1000:
m = 1.5 kg * 1000 g/kg = 1500 g
Now we can calculate the heat (Q):
Q = mcΔT
= (1500 g) * (4.18 J/g℃) * (100℃ - 15℃)
2) For the second question, we need to find the heat that needs to be added to raise the temperature of the frozen water from 7.0℃ to 25℃. The mass (m) is given as 3.0 kg, and the specific heat capacity (c) for water is still 4.18 J/g℃.
The change in temperature (ΔT) is the difference between the final temperature (25℃) and the initial temperature (7.0℃).
Now we can calculate the heat (Q):
Q = mcΔT
= (3000 g) * (4.18 J/g℃) * (25℃ - 7.0℃)
By plugging in the numbers and performing the calculations, you can find the answers to both questions.