Level 3: Falling, measured

Gravity and orbits · level 3 of 8 · rough age 9-10 (a guide for parents; anyone can start anywhere)

In this level you put numbers on falling. You time a fall and find that a falling thing gains the same speed every second, see how air holds things back and why parachutes work, trace the curve of a thrown ball, and find out what it would be like to live in 0.38 g, the pull of Mars. It ends with the tides, gravity stretching a whole ocean.

Lesson	You will be able to
Timing a fall	Use "about 10 m/s faster every second" to find a falling thing's speed, on Earth and on Mars
Air gets in the way	Explain air resistance and why a falling thing stops speeding up
Parachutes	Explain how a parachute slows a fall, and why Mars needs very big ones
The shape of a throw	Describe the curve of a throw, find the best angle, and compare throws on two planets
A world at 0.38 g	Say what "g" means and how walking, pouring, building and the human body would change on Mars
Tides	Explain why the sea has two high tides a day, and what Phobos does to Mars

Previous: Level 2: Weight and pull · Next: Level 4: Gravity everywhere · Gravity and orbits topic page