Why does an object fall?

                                  Aristotle                                                          Galileo

During this lesson we are going to investigate the effect of gravity on different objects.  Almost 2500 years ago in Greece, Aristotle thought that heavier objects fall faster than lighter objects. 400 years ago in Italy, Galileo thought that all objects fell at the same speed, no matter how heavy they were. We are going to test the ideas of both the scientists above and see whose idea was correct.

Below are some videos which will help you see who was right. www.bbc.co.uk/education/clips/zqshfg8

 Of course, Galileo was correct because when we drop two objects of similar shapes but different weights, they both fall to the ground at the same time. This is because their air resistance is similar. However if two objects of different shapes but similar weights are dropped, they may land at different times because their air resistance is different.

Homework: You are going to use your understanding of air resistance to make a parachute. Below are the instructions. We will test the parachutes with play-dough eggs at school to see whose will float an egg down to Earth without breaking it, so think about how to cushion the egg too. Here is a video to help you with your ideas. We will test them at school, so do not worry about testing them with plasticine eggs at home. www.bbc.co.uk/education/clips/zgx76sg