Light and Sound

Light and Sound

By Loretta Clubb

​Unlike a flat mirror, the curved surface of the spoon’s bowl bounces incoming rays back towards a central focus point lying between your face and the centre of the spoon’s. In passing through this point, rays from the upper part of your face are reflected downward, while those from the lower part are reflected upward. The result is an upside-down image of your face.

Multiple Choice

When Timothy looks at himself in a spoon, why does he see himself upside down?

• Light is reflecting off of the spoon.

• Light is refracting into the spoon.

• The spoon is refracting light.

• The spoon is absorbing light.

​Have you ever wondered why you can see things in a mirror? This happens because mirrors are very smooth and shiny. Light reflects, or bounces off, the smooth and shiny surface of mirrors. When you see your face in a mirror, you are seeing light bouncing off your face striking and reflecting off the mirror. The way light bounces off mirrors is very much like the way a ball bounces off a wall or the floor. If you throw a ball straight down, it will bounce straight back at you. You can bounce a ball at an angle, and it will bounce off at the same angle. Light reflectsoff a mirror the same way. This is called the angle of incident.

Multiple Choice

To better understand how light travels, Joshua is studying his reflection in the mirror as shown in the picture. Which statement describes why Joshua can see himself in the mirror?

• Light that is traveling in a straight line hits the mirror and goes back toward Joshua.

• Light travels through the other side of the mirror to make a picture of Joshua.

• Light is being absorbed by the mirror that then makes a picture of Joshua.

• Light bends straight up along the mirror and goes away from Joshua.

​​Rule of ReflectionRays of light follow a simple reflection rule: the angle of the incoming ray is equal to the angle of the outgoing ray of light reflecting back. Another way of saying that is the angle of incidence equals the angle of reflection. For example, a flashlight beam will reflect at the same incoming angle.

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Multiple Choice

Josh is investigating what happens in a dark room when he turns on his flashlight and passes the light beam through the room. What will most likely happen if the light beam reaches a mirror?

• The light beam will be reflected by the mirror and bounce back toward him.

• The light beam will be refracted by the mirror and bounce back toward him.

• The light beam will be reflected by the mirror and continue in the same direction.

• The light beam will be refracted by the mirror and

  continue in the same direction.

Multiple Choice

Jayla wants to investigate how light is reflected by a mirror. She shines a laser light on a mirror. Which picture shows the path of the light?

Multiple Choice

Makenzie is investigating the path light will travel when a light source is shined on a mirror. Which diagram shows the results of her investigation?

Multiple Choice

Which picture shows the angle that light would be reflected after hitting a flat mirror?

Multiple Choice

Nancy wants to see what happens when she takes a picture of herself while looking in the mirror. She found that the picture has a bright circle from her camera's flash. Which best explains the reason for this?

• The light is reflected off the mirror and into her picture.

• The light is absorbed by the mirror and into her picture.

• The light is traveling through the mirror, causing a bright circle on it.

• The light is absorbed by the camera, causing a bright circle on the picture.

​​Although light generally travels in a straight line, it will usually change direction when it passes from one medium into another. The refraction of light also causes rainbows. As the light travels through drops of rain, different colors change direction by different amounts, which results in a rainbow of many colors. Prisms also demonstrate the refraction/bending of different colors by different amounts.

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​Some text here about the topic of discussion.

Refraction of light is when the light bends as it passes through an object.

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Multiple Choice

Carl learned that white light is light that contains all of the colors of the rainbow. He noticed when white light is shot at a glass prism, it splits the light into all of its individual colors. What conclusion can Carl make to explain what he is seeing?

• Light is destroyed when moving from the air into another material.

• Light is absorbed when moving from the air into another material.

• Light is reflected when moving from the air into another material.

• Light bends when moving from the air into another material.

Multiple Choice

Which of the below statements describes a prism?

• focuses light

• absorbs light

• refracts light

• dims light

​Light can also be refracted, meaning its rays can be “bentwhen traveling from one medium to another. Because light travels more slowly in water than in air, a pencil placed in a cup of water will appear broken at the point of entry into the water.

Multiple Choice

What is happening to light that makes the pencil appear to be bent or broken?

• Light is being reflected.

• Light is being refracted.

• Light is being absorbed.

• Light is being spread out.

Multiple Choice

What happens to the light when it enters the prism?

• The ray of light straightens as it strikes the glass.

• The ray of light transforms to heat when it strikes the glass

• The ray of light bends as it strikes the glass.

• The ray of light becomes shorter when it strikes the glass.

​Sound vibrations are produced in many ways. Voices produce sound by vibrating bands of muscles in the larynx. Many instruments produce sound by being struck or strummed. Blowing air through tubes with air-stop valves produces sound vibrations in horns, like trumpets and tubas. Sound travels in waves from the source outward in all directions. When the vibrating wave of air enters the ear and strikes the eardrum, the eardrum begins to vibrate, sending signals via nerves to the brain where the sound is “heardor identified by the brain. differently. The strength of the vibrations affects how loud a sound is, or its volume. Striking the key on a piano or the bar on a xylophone with a lighter touch produces a sound with a lower volume. Striking the key or bar more sharply, or with more force, will cause a louder sound.

Multiple Choice

Jai'liyah is clapping her hands at a concert. If she uses more force to clap her hands, the sound will most likely become

• louder in volume

• softer in volume

• higher in pitch

• lower in pitch

Multiple Choice

The UPS man knocks on the outside of a wooden door. Which best explains why the person inside the house can hear the knock?

• The knock creates sound through space on the wooden door.

• The knock creates sound through gravity on the wooden door.

• The knock creates sound through electricity on the wooden door.

• The knock creates sound through vibrations on the wooden door.

Multiple Choice

The barn on a farm has a tin roof. Whenever it rains, it is very loud in the barn. What most likely causes so much noise in the barn when it rains?

• rain rusting the metal roof

• rain vibrating the metal roof

• lightning shaking the metal roof

• lightning reflecting off the metal roof

Multiple Choice

Which of the following is required for sound?

• chemicals

• vibrations

• water

• instruments

Multiple Choice

Johanna has a high-pitched voice. Peyton has a low-pitched

voice. What is most likely true?

• Johanna's vocal cords vibrate faster than Peyton's.

• Johanna's vocal cords produce straighter waves than Peyton's.

• Peyton moves air over his vocal cords at a faster rate than Johanna.

• Peyton's vocal cords produce more sound waves per second than Johanna's.