FORCES have different effects on bodies.

 They can act by contact       or     at a distance

You can see how gravity works watching Bill Nye. He is crazy!!!!

Once we've learnt about gravity, sing with me this rap about G-R-A-V-I-T-Y!

If you need, you can look at the lyrics.

MACHINES

We are going to learn about machines. As you know, machines are the objects we use to make our life easier and save time.

Machines need energy to function. Some use human energy, some need electricity or fuel.

We have SIMPLE MACHINES and COMPLEX MACHINES. 

Watch a video related to simple machines and forces.

Do you know what's the difference between them? Click

You can click on this  to see if you understood how machines are.

Use this web to play lots of games related to this unit. Click on the picture.

Friction is a force between two surfaces that slows down moving objects.

Did you know that friction releases heat?

Speed tells us how fast something moves. To calculate speed, we divide the distance by the time it takes to travel this distance.

Speed and velocity are not the same. Find out why.

Gravity is also a force. It is always with us and we can always feel its effects.

There are several types of simple machines. Here you are the most relevant ones.

Would you like to check how many simple machines do you know? Let´s play a game then.

Now let´s get deeper into levers. There are three types of them, depending on where we locate their three different elements: force, fulcrum and load.