Learning Library
Who we are
Guidance

# Falling Objects Revisited

(15 ratings )

The purpose of this experiment is to test various objects to determine whether they fall at the same rate.

• What does Newton’s second law of motion state?
• How did Galileo discover that objects fall at the same rate?
• Why did Galileo stipulate that objects fall at the same rate in a vacuum?
• What role does air resistance play in the downward acceleration of an object?
• What is terminal velocity?

400 years ago, the famous physist Galileo discovered that falling objects accelerate at the same rate of speed. It does not matter whether you drop a penny or a shot put out a third story window, the two objects will fall at the same rate and reach the ground at the same time. This constant acceleration was later discovered to be the force of gravity. Though his theory was correct, not all objects will fall at the same rate because gravity is not the only force acting on them. Air resistance and lift create forces that push a falling object away from the center of the Earth’s gravity, slowing the speed of descent.

• Various objects that can be dropped out of a second or third story window. Include a feather and a piece of paper in the objects.
• A friend to make observations at the bottom.
• A notebook
• A pencil

### e:

1. Find a friend who can help you make observations and drop objects out of windows.
2. Collect an assortment of different objects that you will drop. Make sure you have a feather and a piece of paper among the objects. Make sure it is okay to break any of the objects that you drop.
3. Find a second or third story window that you can drop objects out of.
4. Go up to the window with all the objects. Your friend stays on the ground and observes from a safe distance.
5. Hold one object in each hand.
6. Announce to your friend which objects you are testing.
7. You friend should write the names of these objects in a notebook.
8. Drop the objects out the window at exactly the same time. It is important that you simply drop them; do not throw them out the window as this will add force that you cannot account for in the experiment.
9. Your friend observes and records whether one object landed first or both landed at the same time.
10. Repeat steps 5-9 until you have dropped all the objects out the window.
11. Reverse roles with your friend and repeat the experiment.

Terms/Concepts: Gravity; Free fall; Weight; Mass; Force; Constanct speed; Air resistance; Lift; Acceleration; Center of gravity; Newton’s second law of motion; Vacuum; Terminal velocity

References:

Disclaimer and Safety Precautions

Education.com provides the Science Fair Project Ideas for informational purposes only. Education.com does not make any guarantee or representation regarding the Science Fair Project Ideas and is not responsible or liable for any loss or damage, directly or indirectly, caused by your use of such information. By accessing the Science Fair Project Ideas, you waive and renounce any claims against Education.com that arise thereof. In addition, your access to Education.com's website and Science Fair Project Ideas is covered by Education.com's Privacy Policy and site Terms of Use, which include limitations on Education.com's liability.

Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state's handbook of Science Safety.

What could we do to improve Education.com?