1. What’s the difference? MASS AND WEIGHT

2. MASS The quantity of matter in an object Always constant Can never be zero Measured with a balance Unit: grams

3. WEIGHT A measure of force, gravity Dependent on mass of object and force of attraction Can be zero Measured with a scale Unit: Newtons

4. MASS AND WEIGHT BY LOCATION Gravity is constant, so mass and weight are the same on Earth Varies in space and on other planets

5. PROBLEM SOLVED! We are concerned with mass, as it is constant in time and place