A red ladybug appears red in white light, red in red light, and black in blue light. Those would be the proper selections you'd need.
Answer:
f3 = 102 Hz
Explanation:
To find the frequency of the sound produced by the pipe you use the following formula:
![f_n=\frac{nv_s}{4L}](https://tex.z-dn.net/?f=f_n%3D%5Cfrac%7Bnv_s%7D%7B4L%7D)
n: number of the harmonic = 3
vs: speed of sound = 340 m/s
L: length of the pipe = 2.5 m
You replace the values of n, L and vs in order to calculate the frequency:
![f_{3}=\frac{(3)(340m/s)}{4(2.5m)}=102\ Hz](https://tex.z-dn.net/?f=f_%7B3%7D%3D%5Cfrac%7B%283%29%28340m%2Fs%29%7D%7B4%282.5m%29%7D%3D102%5C%20Hz)
hence, the frequency of the third overtone is 102 Hz
There is no apparatus for it. It is either use something like ruler and table and rub together or rub our hands, and friction force will be showed.
Divide distance by speed:
18 meters / 1.5 meters/ second = 12 seconds
Answer: 12 seconds