Lab Quiz: Microwave

Purpose
       The purpose of this lab is to determine the frequency ,dimensions, energy content of the microwaves. We will also determine the number of photons oscillating in the microwave and the pressure the photons exert on the side of the microwave.

Data


Wavelength of microwave = 12 ± 1 cm
Height = 23 ± 1 cm
Width = 35 ± 1 cm
Depth = 35 ± 1 cm
Specific heat of water = 4.186 J/g C
h = planck's constant = 6.626 * 10^(-34) kg m^2/s

for the water:

T_initial = 20 ± 1 C
T_final = 57 ± 1 C
time = 30s
Mass of water = 100g

Data Analysis
c = f*wavelength
f = c / wavelength = 2.59 ± 0.210 GHz

From the calculation above, the frequency is 2.59 ± 0.210 GHz


E = Q = m*c*delta_T =  4.186*100*37 = 15.5 ± 0.570 kJ


Average power of microwave = E/t = 15500/30 = 517 ± 20 W


Number of photon per second = average power / (h * f) = 3.12 * 10^26 ± 2.6 * 10^25


For the pressure of photons exerted on the side of microwave, an assumption that all of the area exerted an equal pressure is made.

Pressure = I / C = power / (Area * C)

Area = 2*( width*depth + width*length + length*depth) = 0.5817 ± 0.0375 m^2

Pressure = power / (Area * C) = 517 / (0.5817 * 3.0*10^8) = 2.98 ± 0.31 µN/m^2