Last week my catapult challenge to you was: Given a range (distance) to your target, can you tune your catapult & projectile to hit your target?
Part of the engineering design process is to measure what you can measure. That gives you data you can use to adjust your designs.
This week, I’ve created a set of projectiles with four different weights that I can use in my catapult game. I also simplified my range by using a yoga mat to clearly mark the minimum distance, and I drew some chalk lines to help me record the distance each projectile travels. Here’s a link to a simple pattern you can use to create your own if you like:
https://putneydesigns.com/wp-content/uploads/2020/11/Catapult-Bean-Bags.pdf
Or, if you know someone who knits (with double pointed needles and can do a circular cast on), try this one out:
https://putneydesigns.com/wp-content/uploads/2020/11/Knit-Balls-pattern-MK-Tufft-IMG_4788.jpg
Join me in this week’s catapult game bonus video as I explore the effect of lever arm angle (release position) on range (distance) for each of my weights. Try it out for yourself! What do you see? Can you collect data and plot it up? Can you use that information to help you win at your catapult game?
When you get your catapult’s range tuned, it should be easy to repeat your results. What are some ways you can make your game more challenging? Maybe spin a dial or roll a dice to determine the distance from the target? Or write some distances down on folded sheets of paper and draw them out of a bowl? Maybe you can award a sliding scale of points for hitting the target out of 3 tries:
- 10 points if you hit it on your first attempt
- 5 points if you hit it on your second try
- 1 points if you hit it on your third try
- 50 points if you hit it on all three tries
I look at lever arm position and projectile weight in this week’s game test. I also try adding a second rubber band to increase the potential energy stored when I extend the lever arm.
Is there something else we could measure?
Join me next week for another look at the engineering design cycle and a new challenge to measure what we can measure as I break down the science behind how a catapult works!
Cheers!
Dr. Marsha Tufft
Subscribe to my YouTube channel for a short new STEM video each week!
