What are the relationships among weight, mass, and volume?

Weight and Mass Weight is the measure of how strongly gravity pulls on something. Earth has a stronger gravitational pull than the moon. Therefore, an object’s weight on the moon is less than its weight on Earth. more gravity = more weight less gravity = less weight

Mass Mass is different from weight. Mass measures the amount of matter that makes up an object or substance. The amount of gravity does not change the amount of mass. Mass can be measured in kilograms. A kilogram of gold and a kilogram of foam have the same mass. However, you need much more foam than gold to make up a kilogram.

Volume = length x width x height Volume measures how much space an object or substance takes up. You can measure the volume of an object with a regular shape, such as a cube. Volume = length x width x height

Volume of object = (volume of water + objects) – (volume of water) Irregular Solids It is easy to measure regular objects like cubes, but what about objects like rocks with irregular shapes? You must use a method called displacement. Small Objects: Choose a container that your small object will fit inside. Pour water into the empty container until it is about half full. Record the volume of water in the container, then carefully add the object. Record the volume of the water plus the object. Calculate the volume of the object using this formula: Volume of object = (volume of water + objects) – (volume of water)

Irregular Solids Large Objects: Fill the over flow can with water until water starts to run out of the spout. Wait until the water stops dripping, then place the graduated cylinder under the spout. Carefully lower the object into the water and observe. A volume of water equal to the volume of the solid will pour out of the spout into the measuring cylinder.

Your Turn You will be given several samples of matter and equipment to measure volume. Follow the guidelines of calculating volume to find the volume of your sample. Record your finding in a chart. Share your chart with a partner and discuss.