Sound waves are vibrations of air particles that travel through a medium, such as air, and can be detected by our ears. These waves carry sound energy and enable us to hear sounds in our surroundings.
When an object vibrates, it causes the air particles around it to vibrate as well. These vibrations create pressure variations in the air, which then propagate as sound waves. The frequency of the vibrations determines the pitch of the sound, while the amplitude of the vibrations affects the sound’s loudness.
Sound waves are longitudinal waves, which means that the particles in the medium vibrate parallel to the direction of wave propagation.
Compressions are regions in a sound wave where air particles are densely packed together, leading to higher air pressure.
Rarefactions are regions in a sound wave where air particles are spread apart, resulting in lower air pressure compared to the surrounding areas.
The electric bell jar experiment was conducted to demonstrate that sound cannot travel through a vacuum, as sound requires a medium to propagate, such as air, water, or solids.
When the bob is displaced by a distance “x” to position “A,” work is done (Fd = Fx) to restore the bob with a force equal in magnitude but opposite in direction to the applied force “F.”
At position “A,” the bob gains maximum potential energy before being released, initiating periodic motion around the mean position “O.” The potential energy is greatest at points “A” and “B,” while the kinetic energy is maximum at position “O” due to the highest velocity.
As the bob moves from “O” to “A” or “O” to “B,” its velocity decreases, resulting in a negative acceleration, which becomes zero at the extreme position. Thus, the acceleration of the bob is directly proportional to the displacement but in the opposite direction. Consequently, the motion of a simple pendulum follows Simple Harmonic Motion (SHM).
The electric bell jar experiment provides evidence that sound waves cannot travel through a vacuum, supporting the understanding that sound propagation relies on the presence of a medium for its transmission.
