# Try This at Home: Milk Jug Mass

## Illustrated Concepts

Mass is the amount of stuff from which something is made. All objects that have mass obey the Law of Inertia. The more mass an object has, the more force required to overcome the object's inertia.

## What You Need

• 2 two-gallon milk jugs with lids
• Water
• Marker

## What To Do

1. Make sure you have an adult with you to supervise this experiment.

2. Fill one milk jug with water. Place lid on firmly. Label milk jug "LOTS OF MASS".

3. Fill the other milk jug less than one quarter full with water. Place lid on firmly. Label milk jug "LITTLE BIT OF MASS".

4. Place both milk jugs on the floor next to a table.

5. Lift the milk jug labeled "LITTLE BIT OF MASS" onto the table. Was this easy or hard?

6. Lift the milk jug labeled "LOTS OF MASS" onto the table. Was this easier or harder to do than lifting the first milk jug?

7. Did you apply more or less force to lift the "LOTS OF MASS" jug compared to the "LITTLE BIT OF MASS" jug? Do both of these jugs obey the Law of Inertia?

8. Clean up.

## What's Happening

The amount of water contained in each jug represents the amount of mass of each jug. The jug with more water has more mass than the jug with less water. The jugs are at rest on the floor until you exert a force on them to lift them to the table. It is easier to lift the "LITTLE BIT OF MASS" jug than it is to lift the "LOTS OF MASS" jug. Objects with more mass require more force to overcome their inertia. Another example of this is when slowing down in a vehicle. A seat belt will need to exert a smaller force to slow down a child's body and a greater force to slow an adultÃ­s body.

### Fun Fact

Due to its inertia, the International Space Station can travel around the Earth at 17,000 miles per hour without using any fuel to keep it going!