Friday, August 6, 2010 at 8:05AM According to Newton's first law of motion, an object moving at constant velocity will continue to move at constant velocity unless an outside unbalanced force is applied. This is why moving objects on Earth will always slow down and stop. The outside unbalanced force that does it is friction. Watch the video to see how friction affects the motion of a marble on a track.
Tuesday, July 20, 2010 at 10:37PM Velocity is speed in a given direction. How is a change in velocity (acceleration) detected? Accelerometers. Most smartphones have accelerometers to detect changes in velocity to monitor certain tasks. The video demonstrates a very basic accelerometer and how it works.
Thursday, June 17, 2010 at 3:50PM
A simple demonstration of centripetal force. A marble is moving in a circular path. The wall of the roll of tape is applying a force on the marble toward the center of the circular path. That is centripetal force. Once the force is removed, the marble, because it has inertia, moves in a straight line.
Thursday, June 17, 2010 at 10:14AM
The more mass an object has, the more inertia it has. Inertia is the tendency of an object to resist a change in motion. There are two fishing weights. One has more mass than the other. A string applies an unbalanced force to the different weights. Which one resists a change in motion? Watch the video.
Thursday, June 10, 2010 at 2:28PM
Another demo on inertia? Yup, and this time I have enlisted the help of one of my favorite science guys: Beaker. Beaker, books, and a rolling chair are moving at constant velocity until an outside unbalanced force is applied. Watch what happens!
