Light Waves Ch.1-2

If a toy sits out in the sun every day for a long time, can light from the sun damage the toy's paint?

• Yes. The paint can take in energy from the light, causing it to be damaged.

• No. Light can only change things by warming them up, so it cannot damage the toy's paint.

• No. Light is not a physical thing, so it cannot change physical things like paint.

• Yes. Light from the sun can pull energy out of the paint, causing it to be damaged.

Answer explanation

Absorb means to take in, so the paint can absorb energy from the light.

We know that when matter absorbs energy, then changes can occur.

How do we know that light carries energy?

• We saw light cause matter to move or change, which is evidence that light carries energy.

• We do not know that light carries energy.

• Because light is bright so there must be energy present.

• We saw light make objects glow in the sim, which is evidence that light carries energy.

Energy is...

• the ability to have power.

• the ability to make something move or change.

• power.

• electricity.

The movement of energy can be tracked by observing the ________ the energy causes to matter.

Answer explanation

We can't see energy with our eyes, but we can still track energy by observing the objects or matter that it causes to move or change.

Remember the flower pots and liquid crystal paper! We couldn't see the energy from the flashlight, but we could see both objects move or change when we shined the flashlight on them.

A light source can emit more than one type of

In our lab, the regular flashlight left the beads white or clear, but the UV flashlight made them change colors. Which claim does this evidence support?

• There is only one type of light that changes material in the same ways.

• There are different types of light that change material in the same ways.

• There are different types of light that can change a material in different ways.

• There is only one type of light.

A scientist measures the amplitude and wavelength of waves in the ocean. The scientist also calculates the amount of energy contained in one square meter of water for each wave. The data and calculations for four different waves are shown in the table.

Which wave characteristics, if any, does the energy in the wave depend on?

• neither amplitude or wavelength

• both amplitude and wavelength

• wavelength only

• amplitude only

Answer explanation

The energy is increasing at the same rate as the aplitude of the wave.

As the amplitude increases, so does the energy. The changes in wavelength do not follow any pattern with the changes in energy.

Different types of light have different_______.

How does increasing the amplitude of a wave affect the sound or light it produces?

• Increasing the amplitude affects the intensity of the wave. Sound waves will be louder, and light waves will be brighter.

• Increasing the amplitude affects the type of wave. Sound waves have a higher amplitude, light waves have a lower ampltiude.

• Increasing the amplitude affects the intensity of the wave. Sound waves will be less loud, and light waves will be less bright.

Answer explanation

If we change the amplitude, it is still the same type of light, but the light gets brighter or more intense.

What happens when the wavelength of a light wave is changed?

• If the wavelength is changed, no characteristics of the wave change.

• If the wavelength is changed, it becomes a sound wave.

• If the wavelength is changed, the brightness of the light being emitted changes.

• If the wavelength is changed, the type of light being emitted changes.

Answer explanation

Notice how the type of light canges as the wavelength shown in the diagram changes.

Gamma rays have short wavelengths (peaks of waves are closer together), and radio waves have longer wavelgths (peaks of waves are spread out more).