Infra-red has wavelengths just longer than visible light.
Answer:
1/f = 1/D' + 1/D
The magnification equation relates the ratio of the image distance and object distance to the ratio of the image height (h^i) and object height (h^o). The magnification equation is stated as follows:
M= H^i/H^o = D^i/D^o
If you clap your hands, the shock causes the air around your hands to begin vibrating. When air particles vibrate, they bump into other particles near them. Then these particles begin to vibrate and bump into even more air particles. When the air particles begin vibrating the air inside your ear, you hear a sound.
