# AP Physics 1 : Longitudinal and Transverse Waves

## Example Questions

### Example Question #1 : Longitudinal And Transverse Waves

At a local concert, a speaker is set up to produce low-pitched base sounds with a frequency range of 20Hz to 200Hz, which can be modeled as  sine waves. In a simplified model, the sound waves the speaker produces can be modeled as a cylindrical pipe with one end closed that travel through the air at a velocity of , where T is the temperature in °C.

What type of waves are sound waves?

Transverse

Electromagnetic

Gravitational

Longitudinal

Longitudinal

Explanation:

Sound waves are longitudinal waves, meaning that the waves propagate by compression and rarefaction of their medium. They are termed longitudinal waves because the particles in the medium through which the wave travels (air molecules in our case) oscillate parallel to the direction of motion. Alternatively, transverse waves oscillate perpendicular to the direction of motion. Common examples of transverse waves include light and, to a basic approximation, waves on the ocean.

### Example Question #2 : Longitudinal And Transverse Waves

Which of these is an example of a longitudinal wave?

A wave produced by a rope oscillating in a plane

Visible light

X-rays

A sound wave

Microwaves

A sound wave

Explanation:

Longitudinal waves transmit energy by compressing and rarefacting the medium in the same direction as they are traveling. Sounds waves are longitudinal waves and travel by compressing the air through which they travel, causing vibration.

Light, X-rays, and microwaves are all examples of electromagnetic waves; even if you cannot recall if they are longitudinal or transverse, they are all members of the same phenomenon and will have the same type of wave transmission. Transverse waves are generated by oscillation within a plane perpendicular to the direction of motion. Oscillating a rope is a transverse wave, as it is not compressing in the direction of motion.

### Example Question #2 : Longitudinal And Transverse Waves

All of the following are transverse waves, except __________.

X-rays

light waves

sound waves

microwaves

sound waves

Explanation:

An important distinction for the MCAT is the difference between transverse and longitudinal waves. Although both wave types are sinusoidal, transverse waves oscillate perpendicular to the direction of propagation, while longitudinal waves oscillate parallel to the direction of propagation.

The most common transverse and longitudinal waves are light waves and sound waves, respectively. All electromagnetic waves (light waves, microwaves, X-rays, radio waves) are transverse. All sound waves are longitudinal.

### Example Question #1 : Longitudinal And Transverse Waves

Which of the following is not an example of a transverse wave?

An earthquake

Plucking a guitar string

A girl holding a jump rope moving her arm up and down

A break dancer doing "the worm"

Jumping up and down on one end of a rope bridge