The condition of weightlessness or free-fall is sometimes called zero gravity but is more accurately known as microgravity. To truly escape Earth’s gravity we would have to be over 6 million kilometres away from Earth – that’s 17 times further away than the Moon.
It is possible to experience microgravity on Earth for short periods of time. Some amusement park rides, like tall roller coasters or vertical drops, achieve a couple of seconds of weightlessness.
This activity explains how to demonstrate microgravity by dropping a Styrofoam cup of water from a height and noting whether water pours out of a hole in the side of the cup.
What You Need
- Download student activity (menu at right)
- Styrofoam or paper cup
- Pencil or other pointed object
- Water
- Bucket or other catch basin
Image: http://www.physics.ucla.edu/demoweb/demomanual/mechanics/gravitational_acceleration/weightlessness.html