#physics#wccc#waves
- Describe the motion of particles within a medium as a mechanical wave passes through the medium:
- The particles oscillate around a mean position, allowing for energy to be transferred through them without a net transfer of matter with zero displacement
- Which of the following statements are true and which are false? For the false statements, rewrite them so they become true.
- A:
Longitudinal Transverse waves occur when particles of the medium vibrate in the opposite direction to the direction of the wave: False, needs to be transverse
- B: Transverse waves are created when the direction of vibration of the particles is at right angles to the direction of the wave: True
- C: A longitudinal wave is able to travel through air: True
- D: The vibrating string of a guitar is an example of a transverse wave: True
- The diagram below represents a slinky spring held at point A by a student.
[Insert Imaginary Diagram]
Draw an image of the pulse a short time after that shown in the diagram and determine the motion of point B. Is point B moving upwards, downwards or is it stationary?
- Point B is moving downwards in the image shown
- Which of the following are examples of mechanical waves?
light, sound, ripples on a pond, vibrations in a rope
- The diagram below shows dots representing the average displacement of air particles at one moment in time as a sound wave travels to the right.
[Insert Imaginary Diagram]
Describe how particles A and B have moved from their equally-spaced undisturbed positions to form the compression.
- They oscillate around their mean position causing them to produce compression in certain areas, which causes them to move back in the other direction.
- A sound wave is emitted from a speaker and heard by Lee who is 50m from the speaker. He made several statements once he heard the sound. Which one or more of the following statements made by Lee would be correct? Explain your answers.
- A: Hearing a sound wave tells me that air particles have travelled from the speaker to me.
- B: Air particles carried energy with them as they travelled from the speaker to me.
- C: Energy has been transferred from the speaker to me.
- D: Energy has been transferred from the speaker to me by the oscillation of air particles.
- Explanation: The particles do not have a net transfer of matter but do transfer energy from the speaker to Lee
- A mechanical wave may be described as transverse or longitudinal. In a transverse wave, how does the motion of the particles compare with the direction of travel of the wave?
- In a transverse wave, the motion of the particles is perpendicular to the direction of the wave
- Classify the waves described below as either longitudinal or transverse:
- A: sound waves - longitudinal
- B: a vibrating guitar string - transverse
- C: slinky moved with an upward pulse - transverse
- D: slinky pushed forwards and backwards - longitudinal
- Mechanical waves generally travel faster in solids than in gases. Provide an explanation for this.
- The particles of the solid are packed closer to each other, meaning that the speed of the oscillations can be faster with same amount of energy due to the smaller distance that has to be travelled for the particles to change direction
- For the wave shown below, describe the direction of energy transfer of the sound between the tuning fork and point X. Justify your answer.
- The direction of energy transfer is parallel to the point of the sound’s origin, meaning it will move directly from the tuning fork to point X