Which is the mechanical wave? A) light waves B) sound waves C) X-rays D) radio waves
Hint: The vibrations in matter or disturbance in matter causes mechanical waves that can be solid, gas, or liquid. Matter through which the waves travel is called a medium. Water waves are formed by vibrations in a liquid and sound waves are formed by vibrations in a gas (air). The mechanical waves travel through a medium which makes the molecules bump with each other.
Complete step by step answer: The waves which always need a medium to propagate or to transfer energy are called mechanical waves. Light waves always travel in a straight line and faster than sound waves. Light waves don’t always need a medium to travel. They can also travel through the vacuum of outer space. We can detect with our eyes. The waves which are produced by vibrations and always require a medium/media to propagate is called a sound wave. They travel as waves. The waves transfer energy from the origin of sound to the environment. X-rays are a type of electromagnetic radiation. The X-rays are produced when high-velocity electrons collide with metal plates. The X-rays come from the air. Soft tissue does not absorb these rays, so it passes through them but dense materials such as bones can absorb their radiations. Radio waves are produced by accelerated charged particles. They can be artificially made by transmitters and also transmit through artificially made products. Hence, sound waves are the only which can travel by particles, atoms, molecules of media.
Therefore, option (B) is the correct option.
Note: The mechanical waves always require initial energy for input. When this energy is added, the wave travels from medium until all of its energy is transferred. These waves can be produced only in a medium that has elasticity and inertia.