Chapter 2 Section 2
1.5 class periods
2-2 Mass and Weight
The purpose of this section is to introduce students to the concepts of mass and weight, two important general properties of matter. Mass is the amount of matter in an object and is measured in grams (g) and kilograms (kg). An object has weight because its mass is attracted by the gravitational force of the Earth. The force of attraction between objects is called gravity.
The themes that can be focused on in this section are patterns of change, systems and interactions, and stability.
Patterns of change: Stress that unless matter is added or taken away from an object, the mass of that object remains constant. The weight of the object, however, can change as the object is moved farther away from the center of the Earth. As such, gravitational forces between objects diminish when the distance between objects increases.
Systems and interactions: All objects interact through gravitational forces between them. The strength of the gravitational force is dependent on the mass of the objects and the distance between them.
Stability: The mass of an object remains constant, or stable, unless matter is added to or taken away from the object. Weight, however, is dependent on both mass and location and is not constant.
Performance Objectives 2-2
Science Terms 2-2