HOW DO YOU KNOW AIR IS THERE?Lesson 2 (part B)

LESSON VOCABULARY

Air: the mixture of gases that surrounds Earth.

Equilibrium: a condition in which opposing forces exactly balance, or equal, each other.

LESSON VOCABULARY

  Force: a push or pull that makes an object move, or change speed or direction, if it is already moving.

 Gravity: the force that attracks things toward the centre of a large object.

LESSON VOCABULARY

Mass: the amount of of matter an object is made up of.

Pressure: a force per unit area.

LESSON VOCABULARY

  Property: a quality or power that belongs specially to somthing (e.g., air exerts pressure)

  Weight: the force that gravity exerts on an object’s mass (e.g., 100 kg is the force that Earth’s gravity exerts on Bob’s mass)

HOW DO WE KNOW THERE IS AIR?

  Different experiments can be done to indicate (show) the presence of air. The presence of air can be seen by investigating its properties.

PROPERTIES OF AIR

air exerts pressure

1. Pressure

air takes up space

2. Space

air has mass

3. Mass