What can improve the speed of domestic cars is

The ways to improve the speed of self-made cars are: motor drive (battery required), rubber band drive, clockwork drive and so on.

1, motor drive.

When the power p of the power plant is constant, the higher u is, the smaller I is. For example, in China, some high-voltage lines use aluminum wires and some use copper wires to reduce costs. Everyone has internal resistance, and with internal resistance, it will heat up. Q=I2R, which can reduce the loss. When going to a small power station, the ultra-high voltage is converted into civil voltage through a transformer.

If you are a switching power supply, you will have this experience: in many cases, the voltage on the device is 100V, so there will be no problem, but if you don't pay attention, once the voltage rises to 220V AC, the whole board will explode. It can be seen that the higher the power supply voltage, the stronger the stress (pressure) resistance of the circuit board is required.

2. Rubber band drive.

The power of the wheel rotation comes from the rubber band. Objects such as rubber bands change shape easily when subjected to external forces. When they change shape, they will generate a force to restore their original shape. This force is called elasticity. Therefore, the rotation of our wheels is driven by the elasticity of the rubber band. The rubber band is wound many times, so it has great elasticity, which acts on the car for a long time and the car travels far.

3, clockwork drive.

The clockwork device is a long rolled steel bar. The central end of the steel bar is fixed on the rotatable shaft, and the peripheral end is fixed on the immovable column. When the spring is tensioned, elastic potential energy is stored. The spring wants to loosen, but because the outer end has been fixed, the spring can only be loosened by rotating the central shaft. In this process, elastic potential energy is released. And the central shaft rotates accordingly.