How are various materials recycled?

Model Car help! How do you build a MOVABLE model car out of recycled materials?

• Hi. My daughter is in a science class, and one of the assignments (which is due tomorrow) is to build a model car out of recyclable materials (that will be RACED in class). She is going to race it down a ramp tomorrow, and we need help. We made the body of the car using a candy box, and the wheels using the tops of plastic grapefruit juice bottles. We were thinking of using bamboo sticks for the axles, but we need help in getting the wheels to move. Since we don't have the time, or money to use a drill to drill a hole in the wheels, what should we do?

• Answer:

  The wheels don't have to move if the entire axle moves. Attach 4 paper clips, loop down, to the box. 2 to each side and run each axle through the loops. If the entire axle turns, as it should, you don't need holes in the bottle caps, just glue them to the ends of the axles. You can use a glue gun to attach those wheels, as well as attaching the paper clips to the candy box. You can improve the appearance by putting the paperclips inside the box and just making a small perforation for the loop to protrude. You need to put some weight in the front of the box in order to get any speed even on a downhill ramp. So tape a rock or fishing weight or something inside the box just forward of the front axle.