Exploring Gravity with a Catapult - Amazon AWS

Exploring Gravity with a Catapult On Ready Jet Go, Jet and his friends learn about gravity, the force that brings us back down when we jump up. In this activity, your child can explore gravity by launching a ball from a catapult and then watching as gravity pulls the ball back down to Earth.

How to Make a Catapult Gravity is the invisible force of attraction that makes our feet stick to the ground and makes us come back down when we jump up. On Earth, we

The Science Behind the Fun Earth and Space Science: Your child is learning that gravity pulls things back down to earth.

may be able to temporarily jump or throw a ball

Engineering and Technology:

into the air, but gravity will bring us back down.

Your child is exploring how simple machines

In this activity, your child will use a combination

such as levers and axles can be used to con-

of simple machines, a lever and an axle, to build

duct scientific investigations.

a catapult, and then use the catapult to conduct a simple investigation showing that when things go up, gravity will bring them back down.

While You Play Before starting the activity, talk about gravity and ask your child to think of times he has noticed gravity in action. 1.

If you jump up in the air, do you always come back down?

2. If you throw a ball into the air, does it always come back down? 3. If you jump off of a diving board, do you land in the pool below? 4. What are some other ways you have seen gravity work?

Vocabulary: Axle pronounced [ak-səl] a rod or spindle (either fixed or rotating) passing through the center of a wheel or group of wheels Lever pronounced [le-vər] a rigid bar resting on a pivot, used to help move a heavy load with one end when pressure is applied to the other Catapult pronounced [kad-ə-pəlt] a device in which accumulated tension is suddenly released to hurl an object some distance After talking about previous experiences with gravity, ask your child to make a prediction: Do you think a ball launched into the air with a catapult will come back down to the ground? Why or why not? Continue asking questions and talking through observations as your child completes the project and conducts the experiment.

Exploring Gravity with a Catapult What you’ll need • Empty tissue box

• Plastic spoon

• Scissors

• Tape

• Two pencils

• Small rubber ball or pom pom balls

• Several rubber bands • Pipe cleaner or a large paper clip

Directions

Step 1 Create a large opening in the tissue box by enlarging the current tissue opening.

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Step 2 Cross two pencils (into a “t” shape) and connect them together with some rubber bands. The horizontal (side-to-side) pencil should be connected to the lower part of the perpendicular (up and down) pencil. The perpendicular pencil will be the launch for the catapult.

Step 3 Make three holes; two on each side of the catapult towards the top and one on the front near the bottom.

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Step 4 Cut two rubber bands open and tie them to together so that you have one long band. Attach one end to a pipe cleaner or large paper clip

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Directions continued

Step 5 Feed the pipe cleaner/paper clip through the hole at the bottom of the catapult in the front so that it anchors the rubber band.

Step 6 Insert the pencils so that the horizontal pencil pokes through the side holes.

Step 7 Create a landing pad by using tape or rubber bands to attach the plastic spoon onto the top part of the pencil, covering the eraser.

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Step 8 Attach the loose end of the rubber band to the spoon and pencil.

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Step 9 Pull back the spoon and attached pencil so that the spoon is facing upward. Place a ball on the spoon. Carefully let go of the spoon so that your hand does not block its movement. The ball should fly through the air for a distance and then fall down to the ground.

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Step 10 Launch the ball several times. Does it always come back down to the ground after a distance of flying? Yes! The force of gravity is pulling the ball back down to earth.

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More ways to play Ready Jet Go! • Gravity Explained Visit: pbskids.org/video/ready-jet-go/2365704332

The contents of this release were developed under a grant from the Department of Education. However, those contents do not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government. The project is funded by a Ready To Learn grant (PR/AWARD No. U295A150003-16, CFDA No. 84.295A) provided by the Department of Education to the Corporation for Public Broadcasting; All rights reserved; Ready Jet Go! and the Ready Jet Go logo are registered trademarks of Jet Propulsion, LLC. © 2017 Jet Propulsion, LLC; PBS KIDS and the PBS KIDS Logo are registered trademarks of Public Broadcasting Service. Used with permission.