Circular motion

Constant acceleration We've studied motion in a straight line by watching Felix step from his gondola, 40 km above the earth. You can skip to about 2 minutes if you want to see the highlights. We've also studied motion in … Continue reading

Parking lot physics

Physics is often best experienced with authentic situations. For example, consider this demonstration of classical mechanics: Here we can see, for example, Newton's first law: an object in motion tends to stay in motion (the truck), and an object at … Continue reading

Escape from Pluto

On a routine research expedition to Pluto, you have an unpleasant encounter with aliens, and wish to leave. Your ship computer indicates you only have enough fuel to quickly accelerate to 1 km/sec. Then you will coast into space, slowing … Continue reading

Magic mass balance

Continuing with my playground theme that I started with the merry-go-round, let's consider the seesaw. What determines whether it will be balanced? Archimedes sorted this out over 2000 years ago, using a scale and weights. Below is a virtual scale. … Continue reading

Centripetal forces at play

This lab partially fulfills competency 6 of the FlexTech physics course. Pre-requisites are completion of Algebra 1 and Geometry, and physics competencies 1, 2, 3, and 4. At some point, you've probably experienced being spun around on some contraption like … Continue reading


From Newton's First Law, we know that an object in motion will stay in motion, unless the object is subjected to an external force. In other words, an object's velocity is constant unless there it is accelerated by some external … Continue reading

Free-body diagrams

Free-body diagrams provide a standard way of describing mechanics problems in a way that is understood across languages. It omits details about what the objects are, and focuses entirely on the external forces acting on the object. Here are rules … Continue reading