| Objective | | | | hooks. The rubber band must be tightly stretched |
| To find out how a submarine uses a propeller and a | | | | between the hook at the bottle's base and the hook |
| stabilizing fin for forward movement. | | | | on the cap. |
| Introduction | | | | - Attach the ruler perpendicular to the water bottle |
| Although the submarine you have seen in a movie | | | | body in the centre with the help of two rubber bands in |
| seems to be gliding along effortlessly, it is actually | | | | the form of an "X". The ruler is your stabilizing fin. |
| fighting the forces of gravity, pressure, friction and | | | | - Now use a waterproof sealant to close all the |
| buoyancy. Have you ever encountered these terms in | | | | paperclip holes in the bottle. |
| previous science fair experiments? Among all other | | | | Your submarine is now ready. |
| science fair experiments, this is one of the best, as you | | | | Testing your Submarine |
| will understand how these forces are overcome by | | | | - Fill three-quarters of the submarine bottle with water |
| the submarine. | | | | and put the cap on. |
| Materials | | | | - Turn the propeller to build potential energy in the |
| A 500ml water bottle, a soda bottle (2 liter), knife, | | | | rubber band. Science fair experiments require that you |
| scissors, 2 large paperclips, needle-nose pliers, | | | | write down all your activities. So count the number of |
| chopsticks, 3 rubber bands, stiff ruler, a silicone sealant, | | | | turns and write this number in your lab book. You must |
| a bathtub or pool | | | | turn the propeller that many times in future. |
| Preparation | | | | Procedure |
| The Propeller | | | | Now you will position the stabilizing fin in the front, |
| This is one of those science fair experiments in which | | | | center and the back in different ways and have some |
| you will need the assistance of an adult. | | | | fun observing how your submarine moves. Record |
| - Cut a soda bottle (2 liter) in half. Take the bottom for | | | | your observation each time. Use the below-mentioned |
| making a propeller with 5 curved separate blades. | | | | ten positions. |
| - Two holes are to be drilled in the propeller, in the | | | | |
| centre and a little off-centre. | | | | 1. No fins- |
| - Cut a small plastic circle out of the remaining 2-litre | | | | 2. Middle: Fin Centered- |
| soda bottle. Bore a hole at the centre of this circular | | | | 3. Middle: Fin moved to the right - |
| piece of plastic and the submarine bottle cap. | | | | 4. Middle: Fin moved to the left - |
| - The free end of a straightened paperclip should be | | | | 5. Front: Fin Centered- |
| passed through the cap of the bottle, the circular | | | | 6. Front: Fin moved to the right - |
| plastic and the centered propeller hole. The free end | | | | 7. Front: Fin moved to the left - |
| should be bent back and passed through the | | | | 8. Back: Fin Centered- |
| non-centered hole in such a way as to keep the cap, | | | | 9. Back: Fin moved to the right - |
| the plastic piece and the propeller in close contact with | | | | 10. Back: Fin moved to the left - |
| each other, but allow the propeller to rotate freely. | | | | The observations will allow you to answer the |
| The Submarine | | | | following questions: |
| - Drill two holes at the bottom of a 500 ml water bottle | | | | - What would happen if there was no stabilizing fin? |
| similar to the propeller holes. | | | | - What is the best position for the fin? |
| - Now feed the straightened end of a paperclip from | | | | - Why is a stabilizing fin important in a submarine? |
| the inside of the bottle through the central hole. Bend | | | | If you're ready to get started with your submarine |
| the free tip and pass it in the non-centered hole. | | | | experiment, your next step is to download a free copy |
| Secure the paperclip in such a way that it will not turn. | | | | of "Easy Steps to Award-Winning Science Fair |
| This part is very tricky, so use a chopstick. | | | | Projects" from the link below right now. |
| - Attach a rubber band between both the paperclip | | | | |