Branch of Science: Physics
Concept: Acceleration Due to Gravity

BOW AND ARROW

This bow and arrow project is a ton of fun to build. It’s even more fun to play with. Test out a physics fact, and have a blast at the same time!

You’ll Need:

• 12 craft sticks
• Ruler
• 2 pencils (1 sharpened and 1 unsharpened)
• Hot glue gun
• 3 corks
• Utility knife
• Rubber band
• 2 twist ties
• Unsharpened pencil
• A friend
• Timer

Safety First: Have an adult help out when using hot glue and sharp tools such as a utility knife. Once finished, don’t release your arrow in the direction of people.

Put It Together:

1. Measure and mark with a pencil the center of each of the craft sticks.
2. Overlap the ends of two sticks to form a 120-degree angle. Hot glue them together.

   

3. Glue another stick to the end of one of these sticks at the same angle. You will form a bow shape.
4. Glue the ends of another stick to connect the center of one angled piece to the center of the middle piece.

   

5. Repeat Step 4 to connect the other angled piece to the middle piece.

   

6. Glue the ends of a sixth stick to connect the centers of the pieces added in steps 4 and 5.
7. Repeat steps 2-6 to make another bow shape.
8. Use the utility knife to cut a cork in half to make two shorter corks.
9. Repeat Step 8 with the other two corks.
10. Sandwich five of the cork pieces between the bows. Glue them at the bow ends, at the angles, and in the center of the straight piece.
11. Stretch the rubber band between the bow ends. Connect each end of the rubber band to a cork with a twist tie.
12. To make the arrow, have an adult help you use the utility knife to cut a slit down the center of the unsharpened end of the pencil wide enough for the rubber band to fit into.
13. Make a horizontal pencil mark on a wall at about your shoulder height.
14. Rest the pencil on the center cork. Slide the slit over the rubber band.
15. Pull back the pencil. Release it perfectly horizontally, even with the mark on the wall. Have your friend time how long it takes to hit the ground.
16. Now have your friend time how long it takes for a pencil to hit the ground when you simply drop it from the height of the mark on the wall. How do the times compare?

Reusable Knowledge

Both pencils should hit the ground at nearly the same time. Why? The answer is gravity. One pencil moves horizontally and the other straight down. But gravity pulls both downward at the same rate.