Calculating Microwave Energy Deposition for Melting Ice and Boiling Water

Click For Summary
SUMMARY

The discussion focuses on calculating the time required to melt ice and boil water using a microwave oven. The key parameters include a microwave wavelength of 0.122 m, a peak magnetic field of 1.3 x 10^-5 T, and a cross-sectional area of 0.00010 m². The total energy required to melt the ice and heat the resulting water to boiling is calculated to be 1505.8 J. The challenge lies in determining the rate of energy deposition from the microwave, which is essential for calculating the necessary heating time.

PREREQUISITES
  • Understanding of microwave energy principles
  • Knowledge of thermodynamics, specifically heat transfer and phase changes
  • Familiarity with electromagnetic field equations
  • Basic calculations involving energy, mass, and specific heat capacity
NEXT STEPS
  • Research microwave energy deposition rates and their calculations
  • Study the specific heat capacity of water and the heat of fusion for ice
  • Learn about the relationship between electromagnetic fields and energy transfer
  • Explore practical applications of microwave heating in food science
USEFUL FOR

This discussion is beneficial for physicists, engineers, and anyone interested in the practical applications of microwave technology in heating processes, particularly in food science and thermodynamics.

Xamfy19
Messages
60
Reaction score
0
I have trouble figuring out the following question. Please help.
------------------------------------------------------------------------
Suppose you want to melt a piece of ice and boil the resulting water by using a microwave oven. The radiation is incident upon one side of the ice which has a cross sectional area of 0.00010 m^2. The microwave only heat the ice and not the glass container. The following data are given:
Microwave wavelength: 0.122 m
Peak Magnetic field of microwaves = 1.3 * 10^-5 T
Ice is a cube with sides equal to 0.010 m
Radiation is only incident upon one side of the ice.
Mass of glass container = 0.20 kg
Initial temperature of ice = 0 degree C

How long do you need to run the Microwave Oven to melt the piece of ice and get the resultant water to boil (assume all heating goes into the water and the incident area remains constant).

-------------------------------------------------------------------------

I calculated the requred heat is 1505.8 J. I thought of using Energy stored per unit volume equation (1/2 B^2/uo). However, I can't connect this result to the total energy required. I also tried to use E = hf. But it only gives me the energy of one photon.

Thanks a lot.
 
Physics news on Phys.org
One has to calculate the mass of the ice and then multiply it by the specific energy required to melt the ice (solid to liquid - heat of formation) and raise it to boiling (0-100°C).

The one has to determine the rate of energy deposition from the microwave system in order to determine the time.
 
Thanks, Astronuc;
I did figure out the energy required to melt ice and water from 0 to 100, which is 1505 J. However, I do have problem determining the rate of energy deposited from microwave. I couldn't find any time-related data (or I just didn't know it) so that it can be used in calculating the rate of energy.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 20 ·
Replies
20
Views
7K
  • · Replies 4 ·
Replies
4
Views
2K