FORCE DIAGRAMS Force is vector Free body diagrams

FORCE DIAGRAMS

• Force is vector • Free body diagrams show force vectors using arrows • Free body diagrams show only the forces that affect a specific object • The sum of the individual forces is called the net force

• A book is at rest on a table top. Diagram the forces acting on the book. • In this diagram, there are normal and gravitational forces on the book.

Illustrate a force diagram: A rightward force is applied to a book in order to move it across a desk. It accelerates from rest. Consider frictional forces.

• The larger applied force arrow pointing to the right since the book is accelerating to the right. • Friction force opposes the direction of motion. • The force due to gravity and normal forces are balanced.

• Like all other vectors, force can be broken down from its resultant force to its component forces • The key to solving these problems is selecting a convenient coordinate system

• How do we determine the x component of the gravitational force? • How do we determine the y component of the gravitational force?

• Newton’s first law of motion is known as the law of inertia: • An object at rest remains at rest, and an object in motion continues in motion with constant velocity, unless the object experiences a net external force. • Essentially, when net force is zero, the acceleration is zero.

• Mass is a measure of inertia • Things with more matter exhibit greater inertia