Experiments
Experiment 1
Equipment Used: · Top Pan Balance · A Range of Materials · Ruler · Calculator · Measuring Cylinder · Water · Light Gates For our first experiment, we wanted to test which material would be the best for submarines to be made of. To find this, we found the density of a range of materials, and then found the speed at which they travelled through the water due to gravity. To find the density, we first measured the mass of each material, using a top pan balance. The uncertainty was very small because the top pan balance is very accurate. However, we still measured each material 3 times and found the average, to ensure we were achieving the right result. Then, we measured the volume of the materials. Since the materials were all cubes, we measured the lengths of each side and multiplied them together. Because the uncertainty of the ruler was ±0.0001, the uncertainty became ±0.0003, due to the multiplication. The equation for density is mass/volume, since the density is the spread of mass over the volume of a material. These are the results we got. From this table we got this graph. We also wanted to work out the speed of the material in water, so, once we worked out the density, we set up an experiment. We filled a clear plastic measuring cylinder with water and placed two light gates 0.82m away from each other. We then used the light gates to time how long the each tube took to travel through both the light gates. These are the results we got: Again, we measured each time thrice and found the average, to ensure the results were more accurate. We then found the speed by dividing the distance by the average time, since the equation for speed is distance/time. From this, we made this graph. We also put in the density values to see how this correlated to the speed in water. There was a trend of the more dense materials having a faster speed, apart from Brass, which had only the 4th highest density, but was the fastest. This experiment relates to the manufacture of submarines in that from our research, we found that submarines are usually made of steel or titanium. Although we did not test titanium, steel is made of iron, which has a fast speed, but is not too dense and heavy. We thought that brass would be the optimal material to make the submarines from, but upon further research, we found that brass is more expensive, and is also much softer and less strong than steel. Thus, steel would be the optimal material on account of these factors. |
Experiment 2
In order to test what the best shape for a submarine would be, we moulded different shapes of plasticine and dropped them through a tube of water, using a light gate to measure the time that each different shape took to fall through the tube.
Materials Used:
Method:
Results:
Conclusion:
The Sphere travelled the fastest through the water, with the hollow cylinder travelling the slowest. The hollow cylinder stopped several times halfway down the cylinder, displaying some degree of buoyancy, perhaps demonstrating the two qualities that would be needed for a submarine, buoyancy and an ability to travel through the water. For this reason, we concluded that a hollow cylinder is the best shape for a submarine to be.
In order to test what the best shape for a submarine would be, we moulded different shapes of plasticine and dropped them through a tube of water, using a light gate to measure the time that each different shape took to fall through the tube.
Materials Used:
- Measuring Cylinder filled with water
- Plasticine
- Light Gates
Method:
- We measured the mass of the plasticine, ensuring that each shape would have the same mass of 18g.
- We moulded each mass of plasticine into different shapes- a sphere, a hollow sphere, a cylinder, a hollow cylinder, a donut ring, and a cube.
- We then filled the measuring cylinder with water and placed it in between the light gates.
- We then dropped each shape into the cylinder to measure the speed at which it fell through the water, measuring each shape 3 time and then taking an average
Results:
Conclusion:
The Sphere travelled the fastest through the water, with the hollow cylinder travelling the slowest. The hollow cylinder stopped several times halfway down the cylinder, displaying some degree of buoyancy, perhaps demonstrating the two qualities that would be needed for a submarine, buoyancy and an ability to travel through the water. For this reason, we concluded that a hollow cylinder is the best shape for a submarine to be.