Three Science Fair Projects About the Power of Gravity
Gravity and Plants
One of the most basic gravity science fair projects has to do with the connection between gravity and plants. Can plants “sense” gravity? In other words, are plants programmed to grow upwards, or do they grow upwards for another reason? To do this project, start off with growing bean plants in foam cups for a week or two until the shoots have grown a bit. Then turn half of them so that the plants are sideways (but make sure that they are still receiving enough sunlight – if you need to, move all of the plants closer to the rims of the cups). Take notes on the plants’ progress each day, as well as the direction in which they are growing, as a basis for your science fair project.
To extend the project a bit, you might want to discuss what you think would happen if an astronaut took a growing plant into outer space. In which direction would the plant probably grow? NASA has done studies on this topic, so consider researching further to see what you can find.
Gravity vs. Air Resistance: A Parachute Experiment
Build a parachute from a square handkerchief, some thread, and a small weight, using this procedure if you need guidance. Then hypothesize about what would happen if you would change various aspects of the parachute. For example, what would happen if the parachute was triangular? What if it was in the shape of a pentagon? Would lengthening or shortening the strings change the speed of the falling parachute? How about making the parachute bigger or smaller, or making it out of a different material? Make several different parachutes and time how long they take to drop from a tall height. Then discuss why some parachutes may have taken longer than others to fall.
Straws and Suction
If you have access to a very tall open staircase (at least five stories high) and a long roll of tubing, you should be able to successfully do a gravity science fair project involving straws and suction. You will also need several assistants to help you.
First, do some research on transpiration. How can an extremely tall tree suck water all the way up its trunk to reach its branches and leaves? It must use an extremely strong force to fight that much gravity. Learn as much as you can about different theories about transpiration.
Then it’s time to try an experiment. Place a bottle of water at the bottom of the stairwell and run the tubing from the bottle up to the first landing. Try to suck the water out of the bottle. Can you do it successfully? Go up another landing and try again. Continue until you reach an elevation at which you can no longer suck the water up all the way. Then repeat the experiment with club soda (or any drink with carbonation). What do you think will change, and why? How does this relate to transpiration in trees?
These gravity science fair projects are unique, and they have real-life applications. Make sure that you document everything and understand your project inside and out before meeting the judges, and you’ll have a good chance of taking home a ribbon!