Home >> Science & Nature >> Science

Interactive Activities About Gravity

Gravity is an essential force in the universe, responsible for holding the solar system together and keeping people's feet firmly on the ground. Gravity is also the weakest force, far weaker than electromagnetic pull or the force holding the nuclei of atoms together. A series of fun interactive activities can demonstrate the force of gravity to children.

Air Resistance
- This activity teaches children that all objects accelerate downward at the same rate because of gravity, regardless of weight. To begin, place a feather and a coin in a clear plastic tube. Ask the children which they expect to fall faster. In all likelihood, they will anticipate that the far heavier coin will fall faster than the feather. Turn the tube upside down, the children will observe that they are correct. Ask the children to explain why they think this happened.
In a Vacuum
- Perform the same experiment using a vacuum pump to suck air out of the tube. Most high school science departments have one. Again, ask the children which object they think will fall faster. This time, the feather and ball will fall at exactly the same speed. In the initial experiment, the feather is slowed by air resistance. Once the air is taken away, the resistance is gone. Both objects accelerate at the same rate because of gravity, so they fall at the same speed.
Center of Gravity
- People are able to stand up under the force of gravity because their center of gravity is located directly above their feet. Leaning forward or backward will cause someone to fall over because the center of gravity has shifted. To prove this, ask the children to bend over and hold their toes, knees slightly bent. Ask them to jump backward. They should be able to do this easily. If you then ask them to jump forward they will find this almost impossible. This is because an object̵7;s center of gravity is located around one point. When a person jumps forward in this position the center of gravity is located too far forward and the person won't be able to recover.
Weak gravity
- Although gravity is what holds every object to the ground, it is a weak force. To demonstrate this, blow up a balloon. Take a straw with a flexible bend and place the long end in your mouth, with the short end pointing up. Try to keep the balloon suspended in midair, by blowing through the straw. This reveals that even the weak force of your breath is strong enough to counteract the pull of gravity.

Science