Science chapter 9 Lessons 5 and 6

Question 1

Sound

Answer 1

Sound happens when matter vibrates or moves quickly back and forth

Question 2

How does sound travel?

Answer 2

All sound travels in waves and forms when matter vibrates. Vibrations in matter cause the particles that make up air to vibrate too.

Question 3

How does energy transfer in a sound wave?

Answer 3

As the sound wave travels, the air particles that make up the wave do not move along with it. They vibrate in place and bump into each other and energy transfers from one particle to the next.

Question 4

Volume

Answer 4

Volume is a property of sound and how loud a sound is

Question 5

How are volume and energy related?

Answer 5

Volume is related to how much energy a sound has.
Example: when you whisper, you make a soft sound. The sound waves you create have little energy. When you shout you use more energy to make a sound.

Question 6

How does sound spread out?

Answer 6

Volume depends on how far away a listener is from the source of the sound. If you are close to the source then it does not have to travel far to your ears and if you are farther then it takes longer to get to your ears and does not seem as loud. The sound waves do not lose energy as they travel away from the source, but energy spreads out in all directions over a large area

Question 7

Pitch

Answer 7

Is how high or low a sound is. Example: a bird makes a high pitched sound and a lion makes a low pitched sound.

Question 8

What does a sounds pitch depend on?

Answer 8

It depends on its frequency or the number of sound waves made in a certain amount of time.

Question 9

High Frequency Sounds

Answer 9

Objects that vibrate quickly and have a high pitch.

Question 10

Low Frequency Sound

Answer 10

Objects that vibrate slowly and have a low pitch.

Question 11

What affects pitch?

Answer 11

The material an object is made of affects pitch. The size and shape of an object affect pitch. Example: a small drum will usually have a higher pitch than a big drum.

Question 12

What are stringed instruments?

Answer 12

Guitars, violins, cellos, and harps are kinds of stringed instruments.

Question 13

How do stringed instruments make sound?

Answer 13

They make sound when you pluck their strings or rub a bow across their strings.

Question 14

What does each strings pitch depend on?

Answer 14

It depends on the strings properties. Example: a thin string vibrates faster than a thick string, so a thin string has higher pitch. In the same way a short or tight string vibrates faster and has a higher pitch than a long and loose string.

Question 15

Electric Charge

Answer 15

An electric charge is a property of some particles that causes them to attract or repel each other.

Question 16

What do particles of matter have?

Answer 16

They have both positive (+)and negative (-)electric charges.

Question 17

What happens when particles have an equal number of positive and negative charges?

Answer 17

The charges balance each other out and the matter has no overall charge.

Question 18

What happens when matter has more negative charges than positive charges?

Answer 18

The matter has an overall negative charge.

Question 19

What happens when matter has more positive charges then negative charges?

Answer 19

The matter has an overall positive charge.

Question 20

What happens when you put two objects with the same charge near each other?

Answer 20

They push away from each other.

Question 21

What happens when you have two objects with opposite charges?

Answer 21

The objects attract each other. Example: rubbing a girl’s hair with a balloon and the balloon picks up the negative charges from the hair. The girls hair has an overall positive charge and the balloon a negative charge so the opposite charges attract each other.

Question 22

Electric Current

Answer 22

The movement of electric charge from one place to another. Example: lighting is an uncontrolled electric current and it can travel in any direction.

Question 23

Electric Circuit

Answer 23

The path that a controlled electric current flows through.

Question 24

What does an electric current need to flow through?

Answer 24

The path must be unbroken for an electric current to flow through a circuit. Every circuit needs a source of energy, such as a battery or an outlet to plug into.

Question 25

Closed circuit

Answer 25

A circuit with no gaps or breaks. An electric current will continue to flow through a closed circuit until it is broken.

Question 26

Open circuit

Answer 26

A circuit with a broken path. Current will not flow through an open circuit.

Question 27

How do you create a break in a circuit?

Answer 27

You can create a break in a circuit by disconnecting a wire from a battery or light bulb.

Question 28

Switch

Answer 28

A device that allows you to open and close the circuit without disconnecting a wire.

Question 29

Why are wires used to build electric circuits.

Answer 29

Wires are usually made of metal with a covering of plastic or rubber and electric charges move easily through metals such as copper, gold, silver, and aluminum.

Question 30

Conductor

Answer 30

A material through which electric charge moves easily.

Question 31

What are some types of conductors?

Answer 31

Metals, mineral graphite, water.

Question 32

Insulators

Answer 32

Materials that stop the movement of electric charge. Examples: rubber, plastic, glass, wood.