The amount of matter in an object.

• Weight

• Mass

• Surface area

• Gravity

The amount of force that pulls objects toward the Earth.

• Weight

• Mass

• Gravity

• Air resistance

The force that pulls objects towards the Earth.

• Mass

• Weight

• Gravity

• Air resistance

The unit used to measure forces

• Kilo

• Meter

• Joules

• Newton

Two forces of the same size that act in opposite directions on an object.

• Air resistance

• Friction

• Balanced

• Unbalanced

The energy transferred when a force makes an object move.

• Gravity

• Work

• Energy

• Power

A force that slows things down.

• Friction

• Lubricate

• Mass

• Gravity

When you use oil to stop moving parts of machine from getting too hot.

• Friction

• Lubricate

• Work

• Weight

The size that covers an object.

• Volume

• Mass

• Surface area

• Length

The force caused by air pushing against moving objects.

• Friction

• Thrust

• Gravity

• Air resistance