Roller Coaster Ride! Have every student line up behind you. Tell them to buckle up and keep their arms and legs inside the car at all times. Then start running in curving pathways. Go slow when you go up a hill and fast when you go down a hill. When the ride comes to a stop, talk about why the roller coaster goes up slowly and down quickly. It’s because gravity pulls the car down, yet gives resistance when it goes up. Therefore when it goes against gravity it needs a force to help pull it up.
What is Gravity?
Once again have all the students line up behind you. Walk around the edges of the gym / room and tell them you have just walked around the whole earth. Now have everyone go to a side of the gym and get out their shovels and start digging. Dig and dig along a straight line until you’ve created a hole that goes from one side of the earth (North America) to the other side of the earth (Indian Ocean). Now get on the edge of the hole and jump in! Walk, jog or run along the straight line you’ve just created with the following speed pattern: slow, medium, fast, really fast, fast, medium, slow . . . suspend . . . repeat going the other direction. Each time you do that speed pattern, travel a shorter line until you’re stuck in the middle of your straight line. This is the center of the earth from where gravity is pulling.
Mass Verses Weight
Now climb out of the hole and start to skip. Notice the weight of your body as it lifts away from the earth and comes back down to the earth during the skip. Try other locomotor steps (walk, run, jump, hop, leap, skip, slide, gallop). Tell your students that their body is mass. The mass stays the same no matter where you are. But the weight of your body will change depending on the strength of the pull of gravity. Let’s go into space to see how this works.
Pretend to fly into outer space. Land on the sun. Suddenly your body feels like it weighs a ton. Try a variety of locomotor steps with an extremely heavy feel. It’s so hard to lift your legs and sometimes you even collapse because you can’t hold up your weight! Did you know that if you weigh 60 pounds on earth, you’ll weigh 1,680 pounds on the sun? That is super heavy!! Now fly to another planet. Call them through different locomotor steps on each planet and adjust the heaviness or lightness according to how much gravitational pull there is.
If you weigh 60 pounds on earth, then you will weigh the following weight on the following planets: (Resource: “Gravity is a Mystery” by Franklin M. Branley)
Hold two balls in your hands. One is heavy and one is light. Ask the students which one will land first. Then drop the balls and show them that they land at the same time. Then explain who Galileo is. Galileo was born in Italy. He was a great scientist, physicist and inventor. He invented telescopes, compasses and thermometers. One day he climbed to the top of the leaning tower of Pisa and dropped two balls of different weights and he discovered that they land at the same time.
Explore with Movement
Have everyone try falling at the same rate. Now have one person lead. Everyone else must fall at the same speed as the leader. Switch who the leader is. Fall in creative ways.
Now hold a flat piece of paper in one hand and a crumbled piece of paper in the other hand. Drop the papers at the same time. Notice the flat paper landed later. That is because of air resistance.
Now have the boys follow one leader while the girls have “air resistance”. The girls need to fall on their own individual timing, yet make sure that they fall slower than the boys, who are moving at the same rate. Switch and let the boys try the “air resistance”.
If desired, you can show Hammer vs. Feather - Physics on the Moon. Discuss that is no air on the moon, so air resistance is not an issue on the moon. Therefore all things will fall at the same rate on the moon.
Create / Perform
Now for fun, tell the students they get one full day without gravity! Get into groups of 5 and have them think of 5 active things they do during the day. (Each child can pick one favorite idea to make sure all kids have a turn to contribute). Then have them dance the ideas as if they had no gravity. Tell them to really exaggerate the idea, or do it up-side-down or sideways. Make sure they move more slow than fast since they can’t control their movement as well without gravity. Have each group perform their dances for the rest of the class.
Review everything they learned in this lesson: What is gravity? What is mass verses weight? How do objects fall? What is air resistance? Who is Galileo? What can overcome gravity? (a force that pulls or pushes)
You can also read them the book Gravity is a Mystery by Franklyn M. Branley.
Gravity is a force which tries to pull two objects toward each other. Anything which has mass also has a gravitational pull. The more massive an object is, the stronger its gravitational pull is. Earth’s gravity is what keeps you on the ground and what causes objects to fall. (https://www.google.com/?gws_rd=ssl#q=gravity+is)Mass Versus Weight: