Mass Volume and Density Metric System Developed by

Mass, Volume and Density

Metric System Developed by the French in the late 1700’s. Based on powers of ten, so it is very easy to use. Used by almost every country in the world, with the notable exception of the USA. Especially used by scientists. Abbreviated SI, which is French for Systeme International.

Mass Mass is the amount of matter that makes up an object. A golf ball and a ping pong ball are the same size, but the golf ball has a lot more matter in it. So the golf ball will have more mass. The SI unit for mass is the gram. A paper clip has a mass of about one gram. The mass of an object will not change unless we add or subtract matter from it.

Measuring Mass We will use a triple beam balance and a digital top-loading scale to measure mass.

Weight and Mass Earth 1 gravity Moon Jupiter 1/6 th gravity 2. 5 gravities Jill’s mass 30 kg Jill’s weight 300 N 50 N 750 N n. Notice that Jill’s mass never changes. Jill is 30 kg of little girl no matter where she goes!

Volume is the amount of space an object consumes. The base unit for volume is the liter. There are two methods for finding volume.

Volume of Regular Objects We can find the volume of box shapes with the formula Volume = length x width x height. In this case the units would be cubic centimeters (cm 3). So a box 2 cm x 3 cm x 5 cm would have a volume of 30 cm 3 5 cm 2 cm 3 cm

Volume of Irregular Objects Ø We measure volume of irregular objects with a graduated cylinder. Ø This method is called water displacement Ø Liquids form a curved surface in graduated cylinders. Ø Take your reading at the low point of the curve or meniscus

Water Displacement Pour 7 ml of water in a graduated cylinder. If a rock causes the level to rise to 9 ml, the rock must have a volume of 2 ml.

Liquid Volume 1 cm 3 = 1 ml 1 cm 3 of water = 1 ml of water = 1 gram of water

Water Mass and Volume 50 ml (50 cm 3) of water would have a mass of 50 grams 1 Liter of water would have a mass of _______? 1 L = 1000 m. L so its mass would be 1000 grams or a kilogram.

Density is the amount of matter (mass) compared to the amount of space (volume) the object occupies.

Density = mass/volume Remember, all fractions are division problems. Since the unit for mass is grams, and the unit for volume is ml or cm 3, then the unit for density is g/ml, or g/ cm 3

Density Formula Wheel Formula wheels make it easy to solve density problems. Cover the property you are trying to find, and do what is left over. To find density, cover the word density. You have mass over volume remaining. So divide mass by volume to find density! Mass Density Volume

Understanding Density In the following illustration, each square will represent 1 cm 3. Each g will represent 1 gram. Mass = 24 g Volume = 8 cm 3 Density = ? g/cm 3 g g g g g g