Sounds are made when things _____.

• vibrate

• vibration

• pluck

Guitar strings vibrate when you ____ them.

• vibrate

• vibration

• pluck

You often cannot see ______, but you can feel them.

• vibrate

• vibration

• pluck

Sound can travel on _____.

• gases (air) only

• solids and gases, but not on liquids

• solids, liquids and gases

Sound travels best or fastest on _____.

• solids

• liquids

• gases

a variable that you keep the same during your investigation

• control variable

• dependent variable

• independent variable

a variable that you can change

• control variable

• dependent variable

• independent variable

the variable that you observe and/or measure

• control variable

• dependent variable

• independent variable

What is the independent variable in the picture?

• the clock

• the color of light

• the kind of water

How low or high a sound is

• volume

• pitch

• decibel