Question

The transfer of energy in mechanical waves happens through molecules by which of the following phenomena?
$(a)$Through collision
$(b)$Through interaction
$(c)$Through cohesive forces
$(d)$Through electrical forces

Answer 1

Hint: We know that mechanical waves require medium to travel. Mechanical waves are oscillation of matter. The particles do not move far from their equilibrium position but they do vibrate and transfer energy to the nearby particles. They propagate as a disturbance.

Complete answer:
We know that mechanical waves are the waves which require medium to travel. They can’t travel in vacuum. Examples of mechanical waves are sound waves, water waves, etc. Mechanical waves are oscillations of matter and transfer energy through a medium (solid, liquid and gas).
Mechanical waves propagate in a medium by vibration of particles from their mean position and not by the actual movement of particles from their mean position. Due to their vibration, particles collide with each other and transfer energy. Therefore energy transfer in mechanical waves is done through collision of molecules with each other.

So, the correct answer is “Option A”.

Additional Information:
We define waves as a propagating disturbance of one or more quantities. On the basis of medium required for propagation, wave is of two types:-
$a.$Mechanical waves- Waves which do require medium to travel are called mechanical waves. Examples – Sound waves, Water waves, seismic waves, etc.
$b.$Non-Mechanical waves- Waves which do not require any medium to travel are called non-mechanical waves. Examples – Light waves, radio waves, etc.
On the basis of direction of propagation, the wave is of two types.
$a.$Transverse waves – The disturbance at each point is perpendicular to the direction of propagation. Example - light wave.
$b.$Longitudinal wave- The disturbance at each point is in the direction of propagation. Example – Sound wave.

Note:
Always, keep in mind that properties of mechanical and non-mechanical waves are different from each other, so never be confused between the working of mechanical waves to that of non-mechanical waves. In a question, we should proceed for the answer by careful analysis of the nature of the given wave.