Materials:
1. Skewers
2. Rubber band
3. Masking tape
4. Plastic spoon
5. Large marshmallow
Procedures:
1. Form a triangle as the base by using 3 marshmallow and 3 skewers
2. Use 3 more skewers and 3 more marshmallows to create a pyramid
3. Use the masking tape to secure the plastic spoon on a skewer
4. Take the rubber band and make a loop around the topmost marshmallow
5. Insert your spoon skewer into the base of the marshmallow and also through the rubber band loop.
6. You can play with this after you construct it, but it is advised to be fragile with the device. For an even stronger catapult, you can wait overnight for the marshmallows to harden, so your device will not break so quickly.
The Science Behind It:
Projectile motion:
- Whether you’re throwing a football or baseball up in the air, all these objects will undergo projectile motion. Projectile motion of an object means that the object will travel in a curved path only under the act of gravity. Gravity is the downward force that keeps everything on the ground, and objects would fall at a rate of 9.8 m/s2. The curved path is a mathematical type of curve called a parabola, which is a symmetric curve. This means that the trip downward for a projectile is a mirror image of the trip up. For you to launch the farthest distance, it is advised to launch at a 45 degree angle.
Energy:
- Elastic potential energy: Think of a time when you pulled a rubber band. The rubber band was very stretchy and elastic. As you pull harder, there is more tension in your rubber band. When there is more tension, there is more elastic potential energy involved. In the case of the catapult, you are pulling the rubber band back to gain enough energy for the launch to occur.
- Kinetic energy: When you are walking or running, you are in motion. In order for this motion to occur, you need kinetic energy. Kinetic energy is the energy that is associated with motion. When the projectile is flying through the air, it starts to gain kinetic energy since it is moving in the air. There was a conversion of energy from the elastic potential energy of the rubber band to kinetic energy.
- Gravitational potential energy: Have you had a time in which you were on a huge roller coaster? Well, at the highest point on your roller coaster ride, you would have the maximum gravitational potential energy. Gravitational potential energy is the energy that is related to an object’s position. With the catapult, when the projectile is at the highest point of its motion, it has the highest GPE. After gaining that GPE, the energy converts back to kinetic energy when it falls back down to the ground.
Reference:
No comments:
Post a Comment