In the demonstration laboratory, the teacher first showed us the experiment of rolling on a cone. Its experimental principle is that the lowest energy principle indicates that the energy of an object or system always tends to the lowest state naturally. In this experiment, the distance between the two guide rails at the lower end is small, and the center of gravity of the cone rises when it stops here; On the contrary, at the high end, the two guide rails are separated, and the cone sinks here, and the center of gravity actually decreases. The experimental phenomenon still conforms to the principle of minimum energy, and its core lies in the balance of rigid body in gravity field, while the freely moving object is always balanced at the position with the minimum gravitational potential energy under the action of gravity.

Experimental report of electromagnetic gun: experimental report of college physics demonstration.

Through this experiment, we know that sometimes the phenomenon and essence are completely opposite.

Two. electromagnetic gun

Then we did the experiment of electromagnetic gun. Electromagnetic gun is an electromagnetic launching system which uses electromagnetic force instead of explosive force of gunpowder to accelerate the projectile. It is mainly composed of power supply, high-speed switch, acceleration device and shell.

Experimental report of electromagnetic gun: experimental report of college physics demonstration.

According to the interaction principle of the magnetic field of the electrified coil, the accelerating coil is fixed in the cylinder. When electrified by alternating current, the alternating magnetic field will generate an induced current in the coil, and the magnetic field of the induced current interacts with the magnetic field of the accelerating coil current, so that the projectile is accelerated.

Experimental report of electromagnetic gun: experimental report of college physics demonstration.

We put the shell in the barrel about 25 cm from the tail, press the start button and fire the shell. Although the scope of shells is very small, we all feel wonderful and happy.