Summary
Mark shows how to measure the height of a cliff (or any drop) just by timing how long an object takes to fall. It connects gravity to a simple stopwatch measurement.
Viewer safety
Ages 7+
Shows a cliff jump into water; frame it as 'measure, don't copy.' Made for a general YouTube audience — an occasional mild or bleeped word can slip in, so preview if your classroom bar is strict.
Our rating is a quick teacher-to-teacher guide — preview before showing.
Teaching resources
Discussion questions
Talk about it
Gravity pulls everything down and speeds it up as it falls. The longer the fall lasts, the higher the drop — so a stopwatch can estimate height.
- Why does an object fall faster the longer it drops?
- How does the fall time help you figure out the height?
- Why is it safer to measure a height this way than to guess by eye?
Quick work-a-long
Vocabulary: gravity, free fall, time, measurement.
Try it: Drop a soft object and time the fall with a stopwatch. Do a taller drop — does the time get longer? Record both.