Small bucket or large bowl, Water, 20 coins of the same weight, Scissors, Aluminum foil, Ruler
1. Fill the bucket with water.
2. Using the ruler to make measurements, cut two 15-cm squares from the aluminum foil.
3 . Wrap one of the squares around 10 coins and squeeze the foil into a tight ball.
4 . Fold the four edges of the second square up to make a small boat. Place 10 pennies in the boat.
5 . Make sure you seal each corner tightly so water cannot leak into the sides from below the boat. Set the boat on the surface of the water in the bucket. Place the ball on the surface of the water.
When you dropped the ball of aluminum foil in the water, it had a completely different result than the boat. Although both pieces of aluminum foil have the same weight, the ball takes up a smaller space than the boat. The amount of water pushed aside by an object equals the force of water pushing upward on the object. The larger boat pushes more water out of the way than the ball and creates enough upward force to cause it to float.