Tuesday, May 20, 2008
Monday, May 12, 2008
Scientific Method
How does density affect water?
Hypothesis: What you think the answer to problems
If a steel ship is placed in water, the water will be displaced, then water pressure will be created, forcing upwards, causing the ship to float because of it's hollow interior. If a steel nail is placed in water, it will sink becasue it has a solid interior, so then there would be no upwards pressure created by water, thus causing it to sink.
Materials: What you use to answer problems
- *Can, or half cut can (represents ship)
- *Steel nail(s)
- *Water
- *Two Buckets/Plastic Bins
- *Water gauge
- *Coins (Penny, Nickle, Dime, & Quarter)
- *Stainless Steel bowl
- *Ruler
Procedure: Steps you take to answer the problem (Variables & controls).
- Get the two clear buckets or plastic bins.
- Fill them up with water (one tap the other sea).
- Put the water pressure gauge in the water.
- Put the can in the water to represent the ship (If you don't have a steel ship).
- Measure how much of the can is below the water and we will check the pressure gauge to see how much pressure is being excerted.
- Take the can out and replace it with a nail.
- Wait until the nail stays put in the water.
- When the nail is still it is safe to measure where the nail is and check the pressure gauge.
- Now the nail for a coin. Lets use a quarter.
- Place the quarteron you index finger.
- Keep the quarter leveled parallel to the water, lower your hand into the water, trying to make the quarter float.
- Slowly pull your hand out from under the coin trying to make no waves in the water as you pull your hand out.
- If the coin stays afloat, count how long it lasts on the surface of the water.
- After the quarter sinks (if it sink), wait untill it is still, then measure it and check the water pressure gauge.
- Do this for both buckets of water, salt and tap, with all coins, and the stainless steel bowl (if available).
*Results: Answer the problem, reported in an organized manner, charts, graphs, & diagrams.
*Conclusion:
- WHY you got the results you did
- NOT if your hypothesis was correct, it may support NOT prove
- NOT your results in sentence form (explain)
We got the results we did because of density, buoyancy, water pressure, and air. Our hypothesis was correct. We proved that air has much to do with the buoyancy of a steel ship in water, and buoyancy is how much pressure is exerted to make the steel ship, or can, to float. As we predicted the cans (ship) did float because of air held in it. We also learned that how much density an object has, and the amount of air contained in it is what helps it to float in the water because of it being displaced. When something is placed in water, water is being moved from its original place. As if it were fighting back for its space, water creates an upward pressure trying to get back to where it was causing the object to float.
