Level 2: Weight and pull

Gravity and orbits · level 2 of 8 · rough age 7-8 (a guide for parents; anyone can start anywhere)

In level 1 you saw that everything falls. In this level you measure the pull: weight. You learn the difference between how much stuff something has and how hard a planet pulls on it, work out your weight on Mars and the Moon, find the balancing point of odd shapes, and follow Newton's famous thought experiment of a cannon on a mountain. It ends with how gravity and a tilted spin give us days, years and seasons, on Earth and on Mars.

Lesson	You will be able to
What weight is	Say that weight is the pull of gravity on a thing, and measure it with a spring or a scale
Mass and weight	Tell mass (how much stuff) from weight (how hard it is pulled), and say which changes on Mars
Weight on other worlds	Work out what you would weigh on Mars, the Moon and Jupiter
The balancing point	Find the centre of mass of a ruler and odd shapes, and say why things tip over
Newton's cannon	Explain how throwing fast enough sideways turns a fall into an orbit
Days, years and seasons	Explain a day, a year and the seasons, and compare them on Mars and Earth

Previous: Level 1: Up and down · Next: Level 3: Falling, measured · Gravity and orbits topic page