If you remember that the density of water is very close to 1.0 g/ml or 1.0 oz/fluid ounce ("a pint's (16 oz) a pound (16 oz) the world around"), you may notice that if a cup is 236.6 ml, as given, it should weigh 236.6 g, not the 226 g given above. The fruit has a density of 1.045 g/ml, while the syrup has a density of 1.15 g/ml, so the fruit will float, being less dense. Baer, Geology Program, Highline Community College, and Dr. This page was written and compiled by Dr. However, the content of Wikipedia articles may change and so you may want to be cautious. Wikipedia's Density page has a general discussion of density and its history, calculation, and units. Wikipedia's specific gravity page has an explanation of what specific gravity is and how it is used and even discusses its use in the geosciences and mineralogy. This includes several related pages including instructions of measuring density using the Archimedes principle. Hyperphysics, at the Georgia State has a page about density and a density converter. It allows you to look at pictures of measurements and to enter data. Or, if you want even more practice, see the links belowĮdinformatics on-line lab on mass, volume and density is put together by NYU. If you think you have a handle on all of the things listed above click on this bar to try some practice problems with worked answers! Oceanography - some ocean currents and ocean circulation is controlled by density.The hypsometric curve - examining the causes of elevation variation on Earth.Rocks - determining the name and composition of a rock by its density.Minerals - determining the name of a mineral through its density.Plate tectonics - mechanisms that drive plate tectonics.Isostasy - determining how high continents will sit on the mantle.Have you ever noticed in a lake or the ocean that water is warmer at the surface and colder at the bottom? This is because the warmer water is slightly less dense and, as a result, floats on the denser, colder water.Have you wondered why hot air balloons rise? When the air is heated, it becomes less dense until the balloon's total density is less than that of the atmosphere A hot air balloon is literally floating on the denser, colder air.Here are some examples of how this explains everyday occurrences: Less dense substances will float on (or rise through) more dense substances. It is defined by dividing the SI unit of mass, the kilogram, by the SI unit of volume, the cubic metre. One of the most critical is that the density of a substance will determine if it will float on another. The kilogram per cubic metre (symbol: kg·m3, or kg/m3) is the unit of density in the International System of Units (SI). Why should I calculate density or specific gravity?ĭensities are critical for many uses. So we divide the basalt (210 lbs/ft 3) by the density of water (62.4 lbs/ft 3), and get S.G.= 3.37. The rounded value of 1 g/ml is what you'll most often see, though. For density, you also need to consider the size, or volume, of the object. Actually, the exact density of water is not really 1 g/ml, but rather a bit less (very, very little less), at 0.9998395 g/ml at 4.0 Celsius (39.2 Fahrenheit). If the density of some lake water is 1.25 g mL 1 and contains 92 g of Na + ions per kg of water, calculate the molality of Na + ions in the lake. Calculate the molarity of N a + ions in this lake water. The mass of sugar is 4.00 cups x 200 g/cup 800 g, and the mass of water is 5.00 cups x 226 g/cup 1130 g or 1.13 x 10 3 g. A very large sponge may weigh a lot (have a high mass), but its density is low because it still weighs very little per unit of volume. If the density of water of a lake is 1.25 g m L 1 and one kg of lake water contains 92 g of N a + ions. The words heavy and light on their own refer to mass, and not density. Students, and even teachers, often confuse mass and density. If you pick up an iron skillet, you expect it to be heavy. You are not surprised when a large sponge is easy to lift. For example, sponges are low in density they have a low mass per unit volume. You probably have an intuitive feeling for density in the materials you use often. For example, gold will always have a density of 19.3 g/cm 3 if a mineral has a density other than that, it isn't gold. It is used quite often in identifying rocks and minerals since the density of substances rarely changes significantly. So, 1 cubic meter of water equals 1 × 10 3 kilograms Kg. Now, plugging these values in the formula above, we get: mass density × volume 1000 × 1 1000. Density is a fundamental concept in the sciences you will see it throughout your studies. The density of water is 1000 kg/m³ (see the densities table below).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |