EOY Bellwork 2: EM Spectrum, Waves, and Sound

What happens to a wave when it bounces back after hitting a barrier?

• Refraction

• Absorption

• Reflection

• Diffraction

Answer explanation

When a wave hits a barrier and bounces back, this phenomenon is called reflection. It occurs when the wave cannot pass through the barrier, causing it to change direction and travel back into the original medium.

Tags

NGSS.MS-PS4-2

What is the term for the bending of waves as they pass from one medium to another?

• Reflection

• Refraction

• Absorption

• Transmission

Answer explanation

The bending of waves as they pass from one medium to another is called refraction. This occurs due to a change in speed as the wave enters a different medium, leading to a change in direction.

Tags

NGSS.MS-PS4-2

What causes a red apple to appear red?

• It absorbs red light

• It reflects red light

• It emits red light

• It refracts red light

Answer explanation

A red apple appears red because it reflects red light. The pigments in the apple's skin absorb other colors of light and reflect red wavelengths, making it look red to our eyes.

Tags

NGSS.MS-PS4-2

Why does a pencil appear bent when placed in a glass of water?

• Because the light waves reflect off the water and glass.

• Because the water absorbs the light waves.

• The light waves refracts because the light slows down when changing mediums.

• Because when the light hits the water the light waves scatter.

Answer explanation

The straw appears bent due to refraction, which occurs when light waves slow down and change direction as they pass from air into water, creating the optical illusion of a bent straw.

Tags

NGSS.MS-PS4-2

Compare the speed of sound in air, water, and steel. Which is the correct order from slowest to fastest?

• Steel, water, air

• Air, water, steel

• Water, air, steel

• Air, steel, water

Answer explanation

The speed of sound is fastest in solids, slower in liquids, and slowest in gases. The particles in a solid are closer together which allows the sound to travel faster though the object, while the particles in a gas are farther apart which makes the sound travel slower.

Tags

NGSS.MS-PS4-2

The _____ waves have the shortest wavelength and ____ waves have the longest wavelength.

• Visible light; terahertz waves
• Gamma rays; radio waves
• X-rays; infrared waves
• Ultraviolet rays; microwave waves

Answer explanation

Radio waves have the longest wavelength in the electromagnetic spectrum, ranging from about 1 millimeter to 100 kilometers, making them longer than infrared waves, visible light, and gamma rays.

Tags

NGSS.HS-PS4-1

Which list below shows the correct order of the electromagnetic spectrum waves from shortest to longest wavelength?

• gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves, radio waves

• visible light, ultraviolet, X-rays, gamma rays, infrared, microwaves, radio waves

• radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays

• X-rays, gamma rays, visible light, infrared, microwaves, radio waves, ultraviolet

Answer explanation

The correct order of the electromagnetic spectrum from shortest to longest wavelength is gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves, and radio waves. This matches the first answer choice.