Different Obstacles Affect Radio Waves

How Do Different Obstacles Affect Radio Waves?
  The purpose of this experiment was to find out which materials block radio waves and thus cause the most interference for remote control devices.
 I became interested in this idea because I wanted to know what objects I have in my house that would cause interference to my R/C car.
 The information gained from this experiment will help if someone is using remote control robotics or devices. It may be useful for scientific reasons, remote exploration as well as recreation. This experiment will benefit all those by determining which materials a R/C car user should avoid transmitting through.
 My hypothesis is that the cement (brick) will give the least interference and that the glass will have the most interference.
 I base my hypothesis on a book series called Elements; the AEE homepage and an encyclopedia called Science & Technology. I also base my hypothesis on my own educated guess that glass has very compressed molecules and a reflective surface, and brick has cracks and spaced out molecules.
The constants in this study were:
[pic]The obstacle used to obstruct the radio wave
[pic]The distance for the radio wave to travel
[pic]The distance for the car (receiver) to travel
[pic]The amount of time it took the car to travel from the beginning court to half court
 The manipulated variable was the amount of time it took the radio wave to penetrate the obstacle (the wood, glass and brick). Then hit the receiver and cause the remote control car to move and then hit the centerline at half court.
  The responding variable was the amount of time it took the car to start up from the beginning court line to then drive and arrive at the half court line.
 To measure the responding variable I used a stopwatch to determine how much time it took the car to go from the beginning of the basketball court to the center of the basketball court.