Written by: on May 6, 2020 @ 8:45 am

Image source: Pixabay.com

A catapult is a lever, a stick or beam, propped up by a fulcrum, the pivot point. The catapult magnifies your force to throw an object. So, you do not need as big of a force to propel a large object, but the larger the force, the farther it goes. In ancient times, catapults were used to throw heavy rocks.

Levers and fulcrums can be used to pick up heavy things like rocks and building materials. Have you ever used a see-saw? That’s a lever and fulcrum! See if you can point out which part of your catapult is the lever, and which is the fulcrum? The craft stick with the spoon is the lever and the stack of other craft sticks is the fulcrum. The spoon beam pivots around the stack to generate the force to launch the load. When you press down on the spoon, it pulls up on the rubber band on the opposite end—this is its potential energy. When the spoon is released, it pulls back up on the rubber band and the pom pom goes flying! The potential energy is converted into energy of motion- kinetic energy. Gravity also does its part as it pulls the object back down to the ground.

Image source: Pixabay.com

Take it Further:

Try launching a bouncy ball with your catapult. Compare it with the pom pom. How far or high did it travel? Did it go as high or far as the catapult?

The catapult also demonstrates Newton’s 3 Laws of motion:

An object at rest stays at rest until a force is applied, and an object will stay in motion until something creates an imbalance in the motion. (First Law) The acceleration produced when a force is applied depends on the mass of the object. (F = Ma; Second Law) Every action causes an equal and opposite reaction. (Third Law)

The pom pom will remain at rest until a force acts on it (the release of the spoon and/or gravity) – First Law

The bouncy ball will not travel as high or far as the pom pom as the bouncy ball has more mass than the pom pom and will require a larger force to travel the same distance and speed as the pom pom – Second Law (Force = Mass X Acceleration)

When the spoon is pushed down, the load (pom pom or bouncy ball) travels upward- in the opposite direction equal to the force applied on it. (Third Law of Action-Reaction)

A catapult is a simple machine that has been around for ages. Have your kids dig up a little history and research when the first catapults were invented and used! Hint; check out the 17th century!

Join our HTHT @ Home Science Experiment to make your own Catapult: https://sciencemadefun.net/downloads/Catapult_EOTD_May%206th.pdf

Image source: Pixabay.com

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Catogories: Experiments: Science Made Fun, hands-on, HTHT, Science

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