How to Make a Plastic Cup Submarine
Submarines not only float across the surface of an ocean or lake, but they also have the ability to dive under the water. According to PBS, submarine operators need to continually make adjustments to get the submarine to rise or sink. The key is to get the weight of the submarine to equal the weight of the force of the water.
Things You'll Need
- 2-liter soda bottle
- Utility knife
- Water
- Liquid dish soap
- Plastic drinking cup
- Pin
- Paper clips
- Metal washers
Instructions
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1
Cut the top portion of your 2-liter soda bottle off with a utility knife. Wash and rinse the bottom portion out to get it ready for use.
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2
Pour water in to the soda bottle until it comes within one-half inch of the surface. Add a drip or two of liquid dish soap.
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3
Flip your plastic drinking cup upside down. Poke a hole in the left and right side of the cup, just above the rim of the cup. Bend a paper clip in to a U shape and stick one side in each of the holes you made with the pin. The submarine may now resemble a football helmet.
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4
Cut one last hole in the bottom of your plastic cup (or the top now that you have flipped it upside down). The hole should be the shape of a kidney bean.
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5
Place the plastic cup submarine in the water and watch how it stays afloat near the top of the water. Push down on the top of the cup. Check to see if the cup dives willingly. Add a few paper clips to the U shape with washers on the end of them. Check again to see if the cup dives willingly. Keep experimenting with the paper clips and washers until you get the submarine to dive.
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Tips & Warnings
Record your observations as you experiment with different weights of paper clips and washers.
Younger children should have a parent or teacher cut the 2-liter soda bottles with the utility knife.
References
Resources
- Photo Credit colurful plastic cups image by Warren Millar from Fotolia.com
