Compare It: Gravity or Air Resistance
As you saw and read on the previous screens, the force of gravity causes an object to accelerate toward the ground. However, the force of air resistance counteracts gravity and affects how fast an object falls. In this activity, you will compare the forces of gravity and air resistance. You will sort the labels into two columns based on whether they describe gravity or air resistance.
Click below to begin the activity. Your teacher will review the answers with you.
Then, before moving on to the final assignment, you may want to watch this lesson's videos again or reread Counteracting Forces 
(PDF).
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Gravity at Earth's Center
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Galileo's Experiment on the Moon
