Answer:
L = 0.24 m = 24 cm
Explanation:
Given:
- Wavelength of the wave λ = 12 cm
- total number of nodes : mode @ each end = 2 , 3 nodes in between = 5 nodes
Find:
How wide is the oven?
Solution:
- The wavelength of the microwave corresponds to a frequency of:
f = c / λ
f = 3.0*10^8 / 0.12
f = 25 * 10^8 Hz
- We have a total of 5 nodes, hence we get m = 4 anti-nodes in our standing wave.
- The frequency of a standing wave @ m of length L fixed at both ends is given by:
f_m = m*c / 2*L m = 1 , 2, 3 , 4, ....
L = m*c / 2*f_m
- Plug in values:
L = 4*3 / 2*25
L = 0.24 m = 24 cm
