The educational model of Einsteinʼs lift consists of a table suspended from an electromagnet. A flexible support is attached to the table. A metal ball is on the support and deforms it. When the electromagnet is deenergized, the table falls, the system goes to a weightless state and the support throws the ball up. A camera carries out frame-by-frame photography of the free-falling model. The resulting photographs are imported into a computer, projected on to a screen with a multimedia projector and analyzed in a lecture with the audience. The experiment proves that a thrown up body moves rectilinearly and uniformly relative to the free-falling model of Einsteinʼs lift. In the second version of the experiment we replace the ball with a water drop lying on the unwettable surface of the table of the model.
We propose to attach a small stroboscopic light source to a moving object and connect the source to a pulse generator with the help of insulated thin flexible multi-cored wires. Students can assemble such a device independently in a school laboratory. The device can be used to obtain trajectories with time marks in students’ research projects in mechanics. In the paper we give an example of the application of stroboscopic photography in a demonstration experiment devoted to inertia.
We propose the use of a laptop with a program generator and a transistor power amplifier to control the frequency, duration and amplitude of the LED stroboscope flashes. Examples of the stroboscopic photographs are given.
The paper presents a series of experiments that demonstrate the phenomenon of electromagnetic induction. These make it possible to determine the direction of the induced current and so confirm Lenz's Law. The simple experiments can be reproduced in a school laboratory and can be recommended for students' project activity.
For conducting laboratory experiments on Fresnel diffraction, the use of a simple point light
source from an LED and the application of a modern smartphone for photographing the diffraction
patterns are proposed. The developed devices allow the experiments to be carried out under
normal laboratory lighting.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.