Covered Wagon Cargo

What you need:

• Cardboard box

• Construction paper

• Craft sticks or straws

• Rubber bands

• Tape

• String

• Cotton balls or paper towels

• A ping pong ball

• Books, towels, pillows or other items to create a road

What you do:

1. Use the cardboard box as the body of your wagon.

2. Put your ping pong ball inside the wagon. This is your cargo for your trip out West.

3. Using rubber bands, string, paper towels, cotton balls, craft sticks and other materials, build a way to keep your cargo from bouncing around.

4. Place construction paper over the opening of the cardboard box and tape it down to make it into your covered wagon.

5. Create a trail by laying books, rolled-up towels, pillows and other objects on the floor.

6. Push or pull your wagon across the trail and see what happens to your cargo.

Questions to ask:

1. What happened to your cargo as you pushed the wagon on the trail?

2. How could you improve your wagon to keep the cargo in place as the wagon moves?

What's the science:

As your wagon rolls over the bumps on the trail, the ground pushes up on the wheels and the wagon. The movement transfers energy to your cargo, causing it to bounce. Engineers design suspension systems and cushioning materials to absorb some of that energy, which creates a smoother ride and protects fragile objects. Nowadays, modern cars use springs and shock-absorbing materials for the same reason—to help passengers and cargo stay safe on rough roads.