Free-fall distance
From /guides/what-physics-actually-is:
dropping a stone, the distance it falls is d = 0.5 * g * t^2, where g is
9.8 m/s² (gravity's acceleration near Earth's surface) and t is the time
falling, in seconds. The guide even checks this formula's units before
trusting it: m/s^2 times s^2 cancels down to plain m - a distance,
exactly what d should be.
The starter expression uses t = 1 - swap in this lesson's real time.
Your task: a stone is dropped from a bridge and falls for 3 seconds
before hitting the water. Using d = 0.5 * 9.8 * t^2, how far did it fall,
in meters?
You'll practice:
- Substituting a value into an exponent (t^2)
- Reading
0.5 * g * t^2 as one expression, not three separate steps
Related reading: What a Model Actually Is →