Chapter 9, Problem 10STP

To determine

To Choose: The correct option.

Answer to Problem 10STP

Option A

Explanation of Solution

Introduction:

When a longitudinal wave travels through any medium, it vibrates the medium particles in the direction of propagation of wave and hence contraction and rarer fraction is formed.

A longitudinal wave vibrates the medium particle in the same direction in which they are travelling.Thus, at some points, the density of particles gets higher and hence contraction in medium is formed while at density of particles gets rarer and hence rarer fraction is formed.

  

Therefore, the yarn tied to the coil moves back and forth as the wave passes.

Given figure represents the same condition then it shows a longitudinal wave. Thus. the yarn does not move up and down as the wave passes.Therefore, the option B is incorrect.

The yarn will move surely as the wave passes. Thus, the option C is incorrect.

The yarn will not just move forward it will come back also as the wave passes. Thus, the option D is incorrect.

Conclusion:

Thus, the option A is correct.