Is the Calculation of Thermal Energy in Mixing Water and Steam Accurate?

Thread starter physicsstudent111
Start date Aug 14, 2022
Tags

Energy Thermal Thermal energy

AI Thread Summary

The calculation for thermal energy in mixing water and steam is confirmed as accurate, yielding a total energy of 7.12 million joules. The formula used combines the heat transfer from warm water and the latent heat of steam. The discussion clarifies that only 2 kg of water is converted to steam, as specified in the problem statement. Attention to significant digits and proper prefix usage is emphasized for precision. Overall, the calculations align with the principles of thermodynamics.

Aug 14, 2022

physicsstudent111

Homework Statement: How much energy is required to change one quarter of 8.0 kg of water at 25 degrees celsuis into steam(100 degrees celcuis)

Relevant Equations: Q=mct
Q=mLv

Q=Qwarm water+Qsteam
Q=mct+mLv
Q=(8kg)(4200J)(100C-25C)+(2kg)(2.3*10 to the power of 6 J/Kg)
Q=7.12*10 to the power of 6 J
Is this the correct answer?

Physics news on Phys.org

Aug 14, 2022

malawi_glenn

Science Advisor

Why only 2kg water turning to steam?

Aug 14, 2022

physicsstudent111

Because that's what the question states

Aug 14, 2022

malawi_glenn

Science Advisor

Ah great, I missed the one quarter.

Answer is correct. Keep in mind correct significant digits and usage of prefix

Last edited: Aug 14, 2022

Aug 14, 2022

physicsstudent111

Thank you!

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .

View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

View full post »

Thread 'A bead-mass oscillatory system problem'

I can't figure out how to find the velocity of the particle at 37 degrees. Basically the bead moves with velocity towards right let's call it v1. The particle moves with some velocity v2. In frame of the bead, the particle is performing circular motion. So v of particle wrt bead would be perpendicular to the string. But how would I find the velocity of particle in ground frame? I tried using vectors to figure it out and the angle is coming out to be extremely long. One equation is by work...

View full post »