This is a simple circuit race car, which as a small car that had 1 wheel moving in a forward direction, using a 3V DC motor. I used 2 C battery and that gave it the power it needed.

To begin, you need to know what a circuit is. A circuit is a roughly circular line, route, or movement that starts and finishes at the same place. (Google) That means that the electrons go out through the positive side of the battery, to the motor, and go back in the negative side. This makes the motor move in a circular motion and spins the wheel.

DC current is direct current, which means it contains a constant voltage or current. AC current is alternating current, which is a changing voltage or current. We are using DC current because it the easiest to work with.

Step 1: Gather Your Materials

Here are the materials you will need:

2 C Batteries
wire
Rulers
Plastic wheels
3V Motor
Nails
Hot glue
popsicle sticks

Step 2: Start to Build

To make your car small, cut the ruler to 15cm long (Or in half). Tape the halves together and it should be no thicker than 6.5 cm. They should be next to each other not on top of each other.

Hot glue the wheel to the motor and the other two wheels to the nails. It has to be right in the middle, if there is no hole to put the nail, or put the nail right in the center. Make sure the sharp part of the nail is facing in.

Step 3: Building the Motor

To build the motor, take your 2 C batteries and your wire, and attach the black wire to the Negative side of the battery and the red to the Positive side, so the motor spins in the right direction. But, to get it's full power, put the red wire on one of the batteries and the black on the other. Take another wire and attach both batteries. Finally, attach the wires to the metal part of the motor.

Step 4: Finish!

To complete your car, glue your batteries onto the car, in the middle so it doesn't weight down the car. Disconnect 1 of the wires so the motor doesn't spin contently. Glue the motor and wheel tot he front of the car, under the car. Take your other wheels, and if you need to raise the car, glue a popsicle stick in the back and glue your wheels on top of that. Now your done!

Step 5: Testing

To test, connect the wires to the right side of the batteries. the wheel might not spin at first, but don't put to much pressure on it. It will go a while, but since the wheel might not be centered, it could turn.