Light and Sound 1) What is sound measured in? Science 15 Exam Review 3) What part of your ear catches vibrations? 2) What makes sounds? 5) Where can you hear echoes? Why do you hear them? 4) How do sound waves move? 6) What is the pitch we hear caused by? 7) Are low frequency sound waves close together or far apart? 8) Can people hear all the sounds that animals make? Why or why not? 10) Does sound move faster through solids liquids, or gases? Why? 9) Which sounds have more energy? Soft or loud? 12) How are electromagnetic waves different from sound waves? 11) Are there sounds in space? Why or why not? 13) Which electromagnetic waves can we see? 14) Which electromagnetic waves can be dangerous? 16) What are some examples of things that are transparent?Opaque? Translucent? 15) What allows you to see most objects? 19) Why does an object appear black? 17) What is white light? 18) If an object appears green, the object is absorbing all wavelengths except which one? 20) When does light refract? 21) What does a prism do to light?

**Light and Sound - Science 15 Exam Review Answers:**<br /><br />1) **What is sound measured in?** Sound is measured in decibels (dB).<br /><br />2) **What makes sounds?** Sounds are made by vibrations. When something vibrates, it causes the air (or other matter) around it to vibrate as well. These vibrations travel as waves to our ears.<br /><br />3) **What part of your ear catches vibrations?** The eardrum catches vibrations.<br /><br />4) **How do sound waves move?** Sound waves move as longitudinal waves. This means the vibrations travel in the same direction as the wave is moving, like a slinky being pushed and pulled.<br /><br />5) **Where can you hear echoes? Why do you hear them?** You can hear echoes in places where sound waves bounce off a hard surface and back to your ears. This happens in large rooms, canyons, or against the sides of buildings.<br /><br />6) **What is the pitch we hear caused by?** The pitch we hear is caused by the frequency of the sound wave. High frequency means high pitch, and low frequency means low pitch.<br /><br />7) **Are low-frequency sound waves close together or far apart?** Low-frequency sound waves are far apart.<br /><br />8) **Can people hear all the sounds that animals make? Why or why not?** No, people cannot hear all the sounds that animals make. Some animals communicate using frequencies that are too high or too low for humans to hear. For example, dogs can hear higher frequencies than humans.<br /><br />9) **Which sounds have more energy? Soft or loud?** Loud sounds have more energy than soft sounds.<br /><br />10) **Does sound move faster through solids, liquids, or gases? Why?** Sound moves fastest through solids. This is because the particles in solids are closer together, allowing the vibrations to be transmitted more quickly. Then liquids, then gases.<br /><br />11) **Are there sounds in space? Why or why not?** No, there are no sounds in space. Sound needs a medium (like air, water, or solids) to travel through. Space is a vacuum, meaning it has no matter for sound waves to travel through.<br /><br />12) **How are electromagnetic waves different from sound waves?** Electromagnetic waves, unlike sound waves, can travel through a vacuum (like space). They are also transverse waves, meaning the vibrations are perpendicular to the direction the wave is traveling.<br /><br />13) **Which electromagnetic waves can we see?** We can see visible light, which is a small part of the electromagnetic spectrum.<br /><br />14) **Which electromagnetic waves can be dangerous?** High-energy electromagnetic waves like X-rays, gamma rays, and ultraviolet (UV) rays can be dangerous in large doses.<br /><br />15) **What allows you to see most objects?** Light reflecting off objects and entering our eyes allows us to see them.<br /><br />16) **What are some examples of things that are transparent? Opaque? Translucent?**<br /> * **Transparent:** Clear glass, air, pure water.<br /> * **Opaque:** Wood, metal, a brick wall.<br /> * **Translucent:** Frosted glass, tissue paper, thin fabric.<br /><br />17) **What is white light?** White light is a mixture of all the colors of visible light.<br /><br />18) **If an object appears green, the object is absorbing all wavelengths except which one?** If an object appears green, it is absorbing all wavelengths of light *except* green, which is reflected back to our eyes.<br /><br />19) **Why does an object appear black?** An object appears black because it absorbs all wavelengths of visible light and reflects very little or none back to our eyes.<br /><br />20) **When does light refract?** Light refracts (bends) when it passes from one medium to another (e.g., from air to water or glass). This happens because the speed of light changes as it enters a different medium.<br /><br />21) **What does a prism do to light?** A prism separates white light into its component colors (the spectrum) by refracting different wavelengths of light at different angles.<br />