Topic: Gravity. Beyond Our Planet Science. A Poppins Book Nook Science Experiment. My Name Is:

Transcription

1 Beyond Our Planet Science A Poppins Book Nook Science Experiment Topic: Gravity My Name Is: Clip Art Braddock 2013 JW Illustrations Melonheadz

2 Beyond Our Planet Science Experiment Topic Gravity Welcome to a fun experiment for children and students to learn about gravity in a hands-on way. To get into space, astronauts have driven, ridden in, and been blasted through the sky to outer space. When they do this, they need a lot of power to get them out of the Earth s atmosphere. Then, when they are done, they fall back to Earth safely. The force that they need to break to get into space and that pulls them back down to Earth is called: Gravity. Use a dictionary to define what gravity is: Now that you know what gravity is, let s look a little deeper at gravity around us, then up in space. Gravity is all around us and pulling on us from all sides. Here are some of the ways that gravity affects us on Earth. The Earth: Since gravity is related to mass, the largest thing on Earth is Earth itself, so it will pull things to it with its gravity. The Moon: The moon pushes on the Earth. As the moon orbits, or moves around, the Earth, the gravity of the moon pulls and pushes on the oceans. The motion of the moon as it rotates around the Earth causes the tides to rise and fall each day, relative to the moon s position and gravity. Since the moon s gravity is based on its mass, the moon s phase does not matter to gravity as the phases are related to reflected light and not mass. The Sun: The sun has the largest mass in our solar system. Because of this large mass, it exerts a push and pull on all the planets that cause them to orbit the sun. So, without the sun the Earth would not orbit the sun each year as there would be no forces acting on the Earth to rotate it. Acceleration: Gravity is a force that creates an acceleration. Since the Earth is always pulling on an object, it is always present in the world. This might seem strange, but if there was no gravity then the atmosphere would just leak out into space and everything on Earth would float around or into space like a hot air balloon.

3 Measuring Gravity: You might be wondering if we can measure gravity? The answer is yes we can. Gravity has been measured and it has also been determined to be constant, or the same. Every time that gravity is measured through experiments it comes out with the same results. When you are older you will most likely study physics. Physics is the study of objects in motion and gravity is one of the best motion forces out there. More on the Moon: So, if the Earth exerts so much force and pull with its gravity, why is the moon not galling towards the Earth? This is a true statement: the moon is falling towards Earth, but Earth s gravity and the moons gravity have hit a point of equilibrium, or rather, the point at which they are equal to each other. This means that the Earth is pulling on the moon and the moon is pushing on the Earth the end result is that the moon stays in its rotation around the Earth and does not fall to Earth. With all your new basic knowledge of gravity, let s do a few fun activities to practice our knowledge. Draw what you think gravity would look like since it cannot be seen.

4 GRAVITY QUESTIONS AND CROSSWORD PUZZLE Using the following word bank, write in the answer to each question and fill in the crossword puzzle below. ACCELERATION ATMOSPHERE GRAVITY MOON PHYSICS SUN 1. The makes the tides rise and fall. 2. When objects gain speed it is called. 3. The gravity of the makes the Earth rotate it. 4. The force that pulls objects to the Earth is called. 5. Without gravity, Earth s would leak into outer space. 6. The study of objects in motion is called

5 Now that we have the science behind gravity done, why not do a hands-on science experiment to test our gravity on a potential space ship recovery system that will get astronauts home safely to planet Earth? Purpose The purpose of this experiment is to create a parachute that breaks the least amount of your Lego model. Materials Needed You will need the following materials for this experiment: Handful of Lego to make into a shape to test 3 square Handkerchiefs of different sizes Thread or yarn Scientific Question This hands-on experiment will test gravity. The concept is to create a small model out of Lego and then test a parachute that should keep it safe. In high school physics you will most likely do something similar with an egg. Scientific Method Under a parent or teacher s supervision, perform the following steps to test gravity: 1. Build your Lego test model. 2. Lay out your handkerchiefs flat and place four holes in them, one in each of their corners. 3. Then, cut two pieces of yarn or twine to the same length and tie it off on two opposite holes on the handkerchief. Then, repeat for the remaining two holes. 4. Place the yarn between the top layers of your Lego model so the Lego snap the yarn between them. 5. Outside, find an open place to throw your experiment straight up into the air. 6. Carefully ball up your handkerchief and model, but do not tightly wrap it, instead, layer it so the it goes handkerchief, yarn, then Lego model so that in flight the parachute can unwrap and deploy. 7. Throw your experiment up into the air. 8. The upwards velocity of your throw will be resisted by gravity. As gravity works on your throw, the models upwards velocity will be opposed, then gravity will take over completely and the object will fall towards the Earth. Hopefully the parachute will open and slow the model down. 9. Once your model is on the ground, check it to see if the Lego model broke. 10. Repeat this with the other handkerchiefs as well to see which, if any, prevented the Lego from breaking apart.

6 Scientific Basis As we learned earlier, gravity pulls objects to Earth. Did you see how this was done? Be sure to mark your findings and observations on your science experiment form. Extension For older children, try different materials and sizes for the parachutes or use different models inside. Also, they can use a stop watch to tie the decent of each material to find the one that slows down the parachute the most by noting which is in the air the longest.

7 Gravity Experiment Title: Materials Used: Question: Hypothesis What I think will happen: Method What I did:

8 Draw a picture of your experiment in the box below. Results: Was my hypothesis correct? Yes No What I learned: