Presentation on theme: "Chapter 10, Section 1 The Nature of Force Monday, March 8, 2010 Pages 312 -- 317."— Presentation transcript:
Chapter 10, Section 1 The Nature of Force Monday, March 8, 2010 Pages 312 -- 317
Objectives Explain how balanced and unbalanced forces are related to motion. State Newton’s First Law of Motion. Define inertia.
Vocabulary Words Force Net force Unbalanced force Balanced forces Inertia
What is Force? In science, force is either a PUSH or PULL. The net force is the overall force on an object after all the forces are added together. When there is net force acting on an object, the forces are unbalanced.
Unbalanced Force Same Direction When 2 forces act in the same direction, the net force is the sum of the two individual forces. Unbalanced forces can cause an object to start moving, stop moving, or change direction (accelerate). In this example, the object will move to the right.
Unbalanced Forces Opposite Directions When forces act in opposite directions, the net force is the difference between the two forces. In this example, the object moves to the left.
Balanced Forces Opposite Directions When two equal forces act in opposite directions, they cancel each other out. Balanced forces acting on an object will not change the object’s motion. In this example, the object doesn’t move.
Newton’s First Law of Motion An object at rest will remain at rest and an object in motion will remain in motion unless acted upon by an unbalanced force. Also called the Law of Inertia. Inertia is the tendency of an object to resist change in its motion.
What is Mass? Mass is the amount of matter in an object. The SI unit of mass is the kilogram (kg). The amount of inertia an object has depends on its mass. The greater the mass of an object, the greater its inertia. Mass can also be defined as a measure of the inertia of an object.