Forces Cause Motion A few days ago you learned about net force. Today we will discuss net force more and you will learn about the findings of a really cool man named Galileo who lived a long time ago! Questions to answer: 1. What is gravity? 2. How is mass related to gravity? 3. How can wind resistance effect an item that is dropped? 4.If you drop a heavy item and a light item which will hit the ground first? Don’t worry, after this activity you will be able to! Now go to the next slide to begin the activity. Be sure to read the instructions carefully and use your science journal as a guide. © Olivia Cason

Step #1 Instructions for what you will do… 1.Click this link: Galileo Drops the BallGalileo Drops the Ball 2. Drag the big ball to Galileo’s right hand & the small ball to his left hand. Watch how they fall and answer question Drag the big ball to Galileo’s right hand and the feather to his left hand. Watch how they fall and answer question Drag the small ball to Galileo’s right hand and the feather to his left hand. Watch how they fall and answer question Now press the Vacuum mode. Drag the big ball to Galileo’s right hand and the small ball to the left hand. Watch how they call and answer question Still in Vacuum mode, drag the big ball to Galileo’s right hand and the feather to the left hand. Click drop and watch how they fall. 7. Read the passage on your science journal Isaac Newton claimed to discover gravity when he was sitting under a tree and an apple fell on his head! Did you know… © Olivia Cason

Answer the questions found in the “Apply What You Learned” part of your journal! 1. Match the word with the correct definition _____Gravity a) The weight of an object _____Massb) The pull of objects towards Earth _____Wind Resistance c) An empty space without any matter/air _____Vacuumd) Drag produced when an object moves through air 2. If a toy car and a cotton ball were dropped in a vacuum, would they land at the same time or at different times? Why? 3.If a toy car and a cotton ball were dropped off of a building with wind resistance, would they land at the same time or at different times? Why? More questions on the next slide! Now, let’s see what you learned… © Olivia Cason

4.What if a big fish and a little fish were dropped at the same time from an airplane, would they land at the same time or different times? 5.Explain (in your own words) the force of gravity. 6.Explain why wind resistance causes some objects to fall slower, but has no effect on other objects. 7. Develop a list of 3 items that would drop slower as a result of wind resistance. 8.Do you believe Galileo’s findings are accurate? Why or why not? Justify your answer. 9. What is one interesting thing you learned from this lesson that you didn’t already know? Now, let’s see what you learned… © Olivia Cason

Show what you know! Now you are going to conduct your own experiment! Pair an object from List #1 with an object from List # 2, drop them simultaneously, and record which item hits the ground first. Once you have done all five experiments write a sentence for each group of objects explaining why the items hit the ground at the same time, or why they hit the ground at different times. Object #1Object #2 PennyPaper Clip RockPencil FeatherMarble EggMagnet BatterySpoon © Olivia Cason