Question

What happens when you strike a metal plate with a metal stick?
$\left( a \right)$ The plate vibrates and produces sound.
$\left( b \right)$ The plate vibrates and does not produce sound.
$\left( c \right)$ The plate does not vibrate but produces sound.
$\left( d \right)$ The plate neither vibrates nor produces sound.

Answer 1

Hint: Production of sound is possible via vibrations. When something vibrates, the vibrations cause a disturbance in the medium and thus sound travels. Since when a metal plate is struck with a metal stick then there is the to and fro motion of the plate. So by using this information, we can correctly choose the correct options.

Complete Step by Step Solution: We hear sound when an object vibrates, which causes movement in surrounding air molecules. They then bump into the molecules close to them, this causes a chain reaction which when reaches our ear, is heard as sound. This chain of disturbance of air molecules can also be referred to as sound waves. Vibrations can or cannot be heard, if the vibrations do not come under our hearing range then we won’t be able to hear them.
From the above paragraph, it is clear that sound is made by vibrations. So, when the metal plate is struck by a metal stick, the metal plate vibrates and thus, it produces sound.

So, the correct option is $\left( a \right)$

Additional information: The slowest vibrations we humans can hear is $20$ vibrations per second. The fastest vibrations we can hear is $20000$ vibrations per second. Animals like cats can hear even faster vibrations. The number of vibrations per second can also be referred to as frequency, which is measured in Hertz.
When we speak, something similar happens, that is, we cause a disturbance in the medium by letting some molecules go out and bump into the air molecules in the medium. They then cause the molecules closer to them to bump into them and therefore form a chain reaction, which, when comes to us, can be heard as sound. As this is caused by the disturbance of the medium, the speed of sound is different depending on the medium. It is comparatively slower in gases and higher in solids.

Note: We should also know that the sound needs the medium to travel and can be anything like solid, liquid or gas. But it cannot travel in vacuum. In human beings, the sound is produced by the vibrations of the vocal cords.