1. Walk-In Open your notebook and write the date and this title: Stored Mechanical Energy and Catapults

2. Catapults How is energy transferred?

3. An object has stored mechanical energy (a kind of PE) when it stores energy because of a push or a pull.

4. Examples of Stored Mechanical Energy Rubber band

5. Slingshot

6. Spring

7. Paddle Ball

8. What is a catapult? A catapult has a place to put something you want to launch (we’ll call it the load), and uses the tension in the arm of the catapult to fling the load through the air! Example: a slingshot

9. Catapults Catapults change STORED MECHANICAL ENERGY to KINETIC ENERGY when the force launches a load.

10. Goal: Start thinking about how energy is transferred from one form to another! How: Each group will design a catapult using the materials in your bin. Materials: whatever is in your bin (things like popsicle sticks, spoons, rubber bands, soup cans, containers, etc.!). YOU MAY NOT PERMANENTLY CHANGE ANY MATERIALS (like breaking something in half, etc.). If you need tape, SEE MRS. RYAN FOR TAPE. You will receive a limited amount to use carefully!

11. What will we launch? When your group has designed a catapult, you may try launching: Cotton balls Small balls of paper Pompoms

12. Launching Guidelines Set your catapult at the edge of the table pointing toward either the screen (groups 1, 3, 5, 7) or the back counter (groups 2, 4, 6, 8). DO NOT AIM THE LOAD AT ANYONE. Pick up the load after it is launched and lands on the floor.

13. Clean Up Arrange your items to look like this:

14. Games with Launching Find another group to challenge to some catapult games! Place each catapult at the edge of the table and try… 1. Place a basket several feet away from the catapult. Each player takes ten turns. The person who launches a cotton ball the most times into the shoebox wins. 2. Same as game one, except this time the person who makes it into the shoebox the most times in a row wins. 3. Make a tower using an rolled-up piece of cardstock. The first person to knock it down wins.