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Gravity and Other Forces. What do forces do?. Make things ---- move move faster move slower change direction also change shape. Big and Little forces. We can measure forces Using a forcemeter. Sir Isaac Newton. Which fruit ?. Newton?. Gravity is a force.
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Gravity and Other Forces www.assignmentpoint.com
What do forces do? Make things ---- move • move faster • move slower • change direction also change shape www.assignmentpoint.com
Big and Little forces We can measure forces Using a forcemeter www.assignmentpoint.com
Sir Isaac Newton www.assignmentpoint.com
Which fruit ? www.assignmentpoint.com
Newton? www.assignmentpoint.com
Gravity is a force • When gravity pulls something towards the Earth - - we call this force the weight. www.assignmentpoint.com
Forces are measured in Newtons Weight of an apple = about 1 Newton www.assignmentpoint.com
Let’s play a game ! www.assignmentpoint.com
Results www.assignmentpoint.com
Forcemeters www.assignmentpoint.com
Now another game! www.assignmentpoint.com
Lifting a ping pong ball Suck ! . straw www.assignmentpoint.com
ping pong ball falling The arrow represents the force of gravity www.assignmentpoint.com
Suck straw gravity The ball does not fall when your sucking force = force of gravity How have I shown this ? www.assignmentpoint.com
Suck Suck Suck straw straw straw gravity Which diagram shows the sucking force equal to the force of gravity? gravity gravity www.assignmentpoint.com
Suck straw gravity The ball does not fall when your upward force = force of gravity www.assignmentpoint.com
Gravity down under • People do not fall off the Earth www.assignmentpoint.com
two objects dropped at the same time www.assignmentpoint.com
On the Moon – Apollo 15 A heavy geological hammer and a falcon feather were dropped from the same height. They hit the lunar surface at the same time. • http://nssdc.gsfc.nasa.gov/planetary/image/featherdrop_sound.mov astronaut David Scott www.assignmentpoint.com NASA pictures
Hippo jump www.assignmentpoint.com
Hippo jump Force of gravity www.assignmentpoint.com
Saved? www.assignmentpoint.com
Hippo is still falling quickly www.assignmentpoint.com
Hippo is still falling quicklybut not getting faster air resistance • How do we know? Force of gravity www.assignmentpoint.com
How can we slow Hippo down? • What can you change? www.assignmentpoint.com
Launching a satellite The cannonball must move very quickly to orbit the earth. The Moon orbits the Earth www.assignmentpoint.com
The Moon The Earth www.assignmentpoint.com
The Moon The Earth www.assignmentpoint.com
On the Moon NASA pictures www.assignmentpoint.com
Very heavy boots- Why? Answers? • No gravity on the Moon • Weightless on the Moon • To stop them floating away • They weigh very much less than on Earth • To stop huge bounces • The Moon’s gravity is very much less than the Earth’s gravity www.assignmentpoint.com
Weightless? • or are they? www.assignmentpoint.com (NASA pictures)
apparently weightless(pictures or animation only –not a demonstration) www.assignmentpoint.com
GRAVITY • Things fall • Things have weight • Things stay in place www.assignmentpoint.com
No Gravity • Would an apple fall? • Would things stay on earth? • What would happen? • What? • Why? • How? keep asking questions -like Newton ! www.assignmentpoint.com