PLEASE ANSWER

Which of the following statements about electromagnetic and mechanical waves is true?

A. Electromagnetic waves must travel through a medium, but mechanical waves do not require a medium.

B. Mechanical waves must travel through a medium, but electromagnetic waves do not require a medium.

C. Mechanical waves sometimes travel through a vacuum, and electromagnetic waves sometimes travel through matter.

D. Electromagnetic waves travel mostly through matter, and mechanical waves travel mostly through a vacuum.

B) Mechanical waves must travel through a medium, electromagnetic waves do not require a medium.

Explanation:

1). Mechanical waves:A mechanical wave is a wave that propagates through a material medium.As the wave travels through the medium,the particles that make up the medium must undergo displacements of various kinds, depending on the nature of the waves.They are of two types: a)Transverse wave

b)Longitudinal wave

a). Transverse waves:In transverse waves,the particle displacement is perpendicular to the direction of the wave propagation.This particles do not move along with the wave,they simply oscillate up and down about the individual position as the wave passes by.E.g,waves produced on a string.

b). Longitudinal waves:In a longitudinal wave,the particle displacement is parallel to the direction of the wave propagation.The particle oscillate back and forth about their equilibrium position.E.g, Sound wave in a gas.

2). Electromagnetic waves:This is a type of wave that require a physical medium for propagation and hence can travel through a vacuum.E.g,Light waves.

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