Hi folks! I have an RC car i play with. It seems to me that the car cant be controlled beyond 40 feet from the wireless joystick.
I heard that radio waves keep traveling farther and farther and forever and ever...if that is so why doesn't my car pick up the signal from the wireless joystick and keep driving farther and farther?
why does it seem to loose communication with the wireless joystick after about 40 feet?
thank you

 

Electromagnetic waves obey the inverse-square law. Hence the signal at the receiver diminishes non-linearly the farther away it is from the transmitter. If you double the distance to the receiver, the signal is reduced by a factor of 4.

 

Are you sure the remote control ("RC") for your car uses radio and not infrared. Both types are available. Infrared is usually has a much more limited range. Its range follows the same inverse-square law as MrChips mentions, but it is just less sensitive.

John