SPS9 EM and Mechanical Waves

Which of the following lists the electromagnetic waves in order of decreasing frequency?

• X-rays, microwaves, infrared rays

• UV rays, visible light, x-rays

• infrared rays, microwaves, radio waves

Answer explanation

Electromagnetic waves are ordered by frequency from highest to lowest as follows: X-rays, UV rays, visible light, infrared rays, microwaves, and radio waves. Thus, the correct order is infrared rays, microwaves, radio waves.

Tags

NGSS.HS-PS4-1

Which material is sound able to travel fastest through? Explain.

• Vacuums of empty space because there are no particles for the sound to have to bounce around.

• Gases because the particles are less packed together so the sound waves can move quickly through it.

• Solids because the particles are closely packed together and the sound waves can bounce off of each particle quickly.

• Liquids because the particles easily slide around on each other so the sound waves can slide with the liquid particles.

Answer explanation

Sound travels fastest through solids because their particles are closely packed together. This allows sound waves to efficiently bounce off each particle, facilitating quicker transmission compared to gases or liquids.

Tags

NGSS.MS-PS4-2

Based on the data table, what material does light travel fastest through?

• empty space

• solids

• liquids

• gases

Answer explanation

Light travels fastest through empty space because it is not impeded by matter. In solids, liquids, and gases, light interacts with particles, which slows it down compared to its speed in a vacuum.

Tags

NGSS.MS-PS4-1

NGSS.MS-PS4-2

Which material is light able to travel faster through? Explain.

• Vacuums of empty space because there are no particles for the light to have to bounce around.

• Gases because the particles are less packed together so the light waves can move quickly through it.

• Liquids because the particles easily slide around on each other so the light waves can slide with the liquid particles.

• Solids because the particles are closely packed together and the light waves can bounce off of each particle quickly.

Answer explanation

Light travels fastest in vacuums because there are no particles to obstruct its path. In gases, liquids, and solids, particles can slow down light as it interacts with them, making vacuums the optimal medium for light speed.

Tags

NGSS.MS-PS4-2

The data table shows the speed of sound through different substances. What can you determine about the density of steel compared to the density of glass based on this data?

• Steel is more dense than glass because sound travels faster in steel. Speed of sound and density have a proportional relationship.

• Steel is more dense than glass because sound travels faster in steel. Speed of sound and density have an inversely proportional relationship.

• Steel is less dense than glass because sound travels faster in steel. Speed of sound and density have a proportional relationship.

• Steel is less dense than glass because sound travels faster in steel. Speed of sound and density have an inversely proportional relationship.

Answer explanation

Steel is more dense than glass because sound travels faster in steel. This indicates a proportional relationship between speed of sound and density, meaning higher density results in higher sound speed.

Tags

NGSS.MS-PS4-1

Which statement correctly describes BOTH sound and light waves?

• Light waves travel slower than sound waves.

• Light and sound waves both travel as mechanical waves.

• Light waves can travel through water, sound waves cannot.

• Light waves can travel through a vacuum, sound waves cannot.

Answer explanation

The correct statement is that light waves can travel through a vacuum, while sound waves require a medium (like air or water) to propagate. This highlights a fundamental difference between the two types of waves.

When you look at a pencil in a jar of water, why does it look broken?

• Light waves slow down from air to water.

• Light waves speed up from air to water.

• The light waves do not change speeds in different media, but they do look different.

• The light waves are bending because water is less dense than air.

Answer explanation

When light waves enter water from air, they slow down, causing refraction. This bending of light makes the pencil appear broken or displaced at the water's surface.

Tags

NGSS.MS-PS4-2

Match the following

• C

• Trough

• D

• crest

• E

• amplitude

• A

• wavelength

• B

• wavelength

Tags

NGSS.MS-PS4-1

Match the use to each type of electromagnetic wave.

Groups:

(a) Microwaves

,

(b) Infrared rays

,

(c) Ultraviolet light

,

(d) Gamma Rays

• treating skin conditions

• treatment of cancer

• remote controls

• cell phones

• night vision goggles

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-4

NGSS.HS-PS4-5

If you increase the width of part A of the wave, you have increased the ​ (a)   which will ​ (b)   the frequency of the wave.

• wavelength
• amplitude
• speed
• decrease
• increase

Answer explanation

A LONGER wavelength with DECREASE the frequency of the wave. Wavelength and frequency are INVERSLY PROPORTIONAL.

Tags

NGSS.MS-PS4-1