Light and Sound

Question 1

Which travels faster, light or sound?

Answer 1

Light is considerably faster - approximately 875,000 times faster

Question 2

How fast is the speed of sound through Earth’s atmosphere in MPH?

Answer 2

767 MPH

Question 3

True/False. Sound travels slower in solids than gases

Answer 3

False - Sound travels the fastest (generally) in solids. It is faster in a solid than a liquid, but it is faster in a liquid than in gas.

Question 4

How does sound travel?

Answer 4

Sound travels in vibrations. It requires a medium (Solid, Liquid, or gas), to travel - in other words, it needs particles to travel. This is because it needs particles to pass on the vibrations

Question 5

What does a higher frequency mean?

Answer 5

A higher pitch of a sound

Question 6

What is frequency?

Answer 6

The number of complete waves passing over a point per second.

Question 7

What is the measure of frequency?

Answer 7

Hertz/Hz

Question 8

Light and Sound are both _____

Answer 8

Waves

Question 9

What is the speed of light?

Answer 9

3 x 10⁸ m/s. It is slightly slower in an atmosphere though

Question 10

What slows down the speed of light?

Answer 10

Matter/Particles. Light travels at its fastest in a vacuum (Where there are no particles), because particles slow light down

Question 11

How much light do mirrors reflect compared to how much light they absorb?

Answer 11

A mirror reflects back all the light that hits it and absorbs none.

Question 12

The angle at which light hits a mirror is called the angle of ____________

Answer 12

The angle of Incidence. It is the angle is hits the mirror at. The angle of reflection is the angle it is reflected back at.

Question 13

Compare the angle of Incidence and angle of Reflection and explain your reasoning.

Answer 13

The angle of Incidence and angle of reflection are both the same, relative to an imaginary line perpendicular (90 degrees) of the mirror face (What we call the ‘Normal’). Whatever angle the angle of Incidence is, the angle of reflection will always be the same.

Question 14

The reflection you see in a mirror is a very clear image, where all the light is being reflected back at you. This is called _________

Answer 14

Specular Reflection

Question 15

Light will not travel through anything _________, but will travel through anything _________.

Answer 15

Light will not travel through anything opaque, but will travel through anything transparent.

Question 16

When will light refract?

Answer 16

Light refracts when it passes from one transparent medium of different density to another. An opaque medium would not let light through, only reflect or absorb it, and refraction only occurs when light passes through an object.

Question 17

Light will bend/refract, towards the normal when traveling from a ______ dense substance, to a ______ dense substance, and will refract away from the normal when traveling through a ______ dense substance to a _____ dense substance.

Answer 17

Light will bend/refract, towards the normal when traveling from a less dense substance, to a more dense substance, and will refract away from the normal when traveling from a more dense substance to a less dense substance.

Question 18

The plural of medium is?

Answer 18

Media

Question 19

Why is the image flipped when we look into a pinhole camera

Answer 19

As the hole is very small, light from the top of the image must come in at an angle, which is the same for the bottom of the image. They eventually cross inside the camera, meaning the image on the tracing paper is flipped.

Question 20

Name all 7 colours in order of their frequency - ascending

Answer 20

Red, Orange, Yellow, Green, Blue, Indigo, Violet.