2. What do you think will happen in
this tug-of-war?
3. Gravity – what is it?
• is an attractional force between objects.
• Gravity acts on the Earth by pullingpulling
objects towards its centre
• Bigger objects have more gravity so
since the Earth is bigger than everything
on the Earth, everything is pulled
towards the Earth!
4. Gravity – what is it?
Which arrow is pointingWhich arrow is pointing
thethe wrongwrong way?way?
7. Who discovered it?
• It was Sir Isaac Newton
that ‘worked-out’ gravity.
• 1643 – 1727
• He was the greatest
English mathematician of
his generation. His work
on optics and gravitation
make him one of the
greatest scientists the
world has known.
8. Who discovered it?
The story goes that he was
sitting under an apple tree
and an apple fell onto his
head. He went to to explore
why it fell down and came up
with a theory and
mathematical equation.. He
named it GRAVITY.
9. But what about gravity on
different planets?
http://www.bbc.co.uk/learningzone/clips/gravity-earth-jupiter-
and-pluto/1599.html
http://www.exploratorium.edu/ronh/weight/
10. But what about gravity on
different planets?
http://www.bbc.co.uk/learningzone/clips/gravity-earth-jupiter-
and-pluto/1599.html
http://www.exploratorium.edu/ronh/weight/
Editor's Notes
Teacher notes This presentation is aimed at KS2. Pupils should understand that: Gravity is the name Newton came up with to explain that all objects with mass attract each other. (He did a lovely equation too but we don’t need to know that!) We’re pulled to the centre of the Earth because its mass is much greater than ours. It is gravity that gives us our weight – and on the moon we weigh less (lass mass than Earth), on Jupiter (greater mass than Earth) we weigh more. Weight is measured in Newtons, (as all forces) and mass is mweasured in Kilos. Our position and orbit in the solar system is determined by gravitatonal pulls – the Sun has a huge mass (11x ours).
Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!
Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!
Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!
Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!
Teacher Notes Although Newton and major scientists aren’t what we have to teach – it’s general knowledge. However, it’s also good to teach as another scientist (Einstein) did turn up in the 2006 SATs. Obviously, gravity wasn’t ‘discovered’ but it was Newton that formulated ideas and named it so. The apple story is not formally recorded and may be apocryphal, but it aids the memory nonetheless (and is fun).
Teacher Notes Although Newton and major scientists aren’t what we have to teach – it’s general knowledge. However, it’s also good to teach as another scientist (Einstein) did turn up in the 2006 SATs. Obviously, gravity wasn’t ‘discovered’ but it was Newton that formulated ideas and named it so. The apple story is not formally recorded and may be apocryphal, but it aids the memory nonetheless (and is fun).
