1D Motion
The Physics of the Plunge: Force, Acceleration, and Terminal Velocity
Step out of an open airplane door and ride gravity and air resistance all the way down. Students trace how a growing drag force cancels out weight to explain why a skydiver stops speeding up — and why a parachute is really just a drag machine.
Open Reading Passage
1D Motion
Galileo's Bells: Timing Gravity with a Tilted Ramp and a Musician's Ear
Galileo couldn't time a falling object by eye, so he tilted the ramp and let his ears do the measuring instead. Students trace how spacing bells at 1, 4, 9, 16, and 25 units apart revealed that distance grows with the square of time — and how the odd-number pattern between them proves the acceleration never changes.
Open Reading Passage