Class 10th Sindh & Karachi board physics notes Chapter number 12 waves and sound 🔊 MCQs, short question with answer, long questions, and numerical problems pdf download.
Waves And Sound
Describe the phenomenon of waves with the help of an experiment
We can define a wave only as “a disturbance in the medium that travels from one side of the medium to the other for the transfer of energy.” For example, provide a tub full of water and a pencil. If we go out by dipping a pencil in a tub of water, clear circular ripple forms on the surface of the water and travels to the edges.
However, if we dip the pencil and go out several times, many waves will form. Now, place some area of the paper over the water. Now put a pencil provider and one end of it in water and then move it fast and downwards, you will see that you will move up and down on the paper and the movement of the pencil will be disturbed. It goes on and on. The tub and energy also move from one side of the tub to the other, but not to the water itself. Such upward and downward moving water companies form waves.
Why do the explosive sounds produced in the sun not heard on the earth?
The explosive sounds produced in the sun are not heard on the earth, because there is a vacuum or space between the sun and earth and we know that a sound requires a material medium to propagate. The sound waves are unable to cross the space where electromagnetic waves like light can pass through the location because they do not require any material medium to propagate that is why the light from the sun reaches the earth where the sound is produced in the sun is not heard on the earth.
Why is the flash of lightning seen earlier than the sound of thunder?
The light waves can travel faster than the sound waves or we can say, the speed of light is greater than the speed of sound, which is why the flash of electricity reaches earlier than the sound of thunder and we see the flash earlier and hear the sound later.