Question

help me out pls


thanks in advance
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Answer 1

1. The medium is required to be elastic so that its particles may revert to their initial position after displacement on either side. In other words, the particles are capable of vibrating about their mean positions

The medium must have inertia in order for the particles to store mechanical energy.

The medium should be frictionless such that them is no loss of energy in propagation of sound through it.

2. Lightning and thunder are produced simultaneously, but the thunder is heard a few seconds after the lightning is seen. This is because the speed of light in air is more than the speed of sound in air.

The speed of light is given as 3×10

8

m/s.

The speed of sound is 340 m/s.

Hence, the flash of lightning is seen before the thunder is heard as the speed of lightning is greater than the speed of thunder.

4.Sound Light

1) Sound is a longitudinal wave. 1) Light is a transverse wave.

2) Sound requires a material medium. 2) Light does not require a material medium.

3) Sound in air moves at hundreds of meters per second. 3) Light in air moves at hundreds of millions of meters per second.

Answer 2

Explanation:

1. Requisites of the medium for propagation of sound: (i) The medium must be elastic. (ii) The medium must have inertia. (iii) The medium should be frictionless.
2. The reason we see a flash of lightning before hearing thunder is because light travels faster than sound. The speed of light depends on what it is moving through - being slow in gases, fast in liquids, and even quicker in solids. In the air, sound travels at around 332 metres per second
3. Gaseous medium (The air inside it). Hence, since solids are good conductors of sound, the sound which you hear first, is transmitted by the iron and the next sound is transmitted by the air particles. So you heat sound twice.
4. The differences between light and sound are as follows: ... Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum.