4th grade light, sound and waves

Question 1

Pitch and loudness: which statement is true?

• A. Sounds get quieter the further you are from the source.
• B. Longer strings make higher notes.
• C. Loud sounds always have a high pitch.
• D. Hitting a drum harder makes a higher note.

Question 2

Waves and energy: which statement is true?

• A. Surfers are carried by water travelling across the whole ocean.
• B. A wave can travel without any energy.
• C. The bigger a sea wave's amplitude, the more energy it carries.
• D. Ripples on a pond carry the stone to the edge.

Question 3

Water is poured into identical glass bottles to different levels. You blow across the tops. Which bottle gives the highest note?

• A. they are all the same
• B. the one with the most water (shortest air column)
• C. the one with the least water
• D. the empty one

Question 4

Which word means the height from the middle (rest) line to a crest?

• A. amplitude
• B. wavelength
• C. crest (peak)
• D. trough

Question 5

In Morse code, WIND is sent as •–– / •• / –• / –••. How many flashes (dots and dashes) is that altogether?

Answer 

Question 6

Pitch and loudness: which statement is NOT true?

• A. Pitch is how high or low a sound is.
• B. Faster vibrations make higher-pitched sounds.
• C. Longer strings make higher notes.
• D. Bigger vibrations make louder sounds.

Question 7

True or false? Sounds get fainter as they travel further from the source.

• A. True
• B. False

Question 8

Phones and computers send pictures and music as patterns of just two signals, like on and off. What is this called?

• A. an echo
• B. digital information
• C. a rainbow
• D. a shadow

Question 9

True or false? Wavelength is measured from one crest to the next.

• A. True
• B. False

Question 10

What is the job of the eyelid?

• A. focuses light onto the back of the eye
• B. the layer at the back that senses light
• C. protects the eye and spreads tears
• D. carries signals from the eye to the brain

Question 11

True or false? Waves transfer energy from place to place.

• A. True
• B. False

Question 12

Can sound travel through this: a vacuum in a sealed jar with all the air pumped out?

• A. sound can travel through it
• B. sound cannot travel through it

Question 13

Two sound waves are drawn the same way. Wave A has an amplitude of 2 squares and wave B has 3 squares. Which is the LOUDER sound?

• A. wave A
• B. wave B

Question 14

A torch (flashlight) flashes short (•) and long (–) pulses. Use the key to decode the message. Key: D = –•• O = ––– G = ––• Message: –•• / ––– / ––•

Answer 

Question 15

In waves on a pond, 3 complete waves fit into 15 cm. What is the wavelength?

Answer cm