PHY 221 Ch 5 Forces and FB Diagram

PHY 221 Ch 5: Forces and FB Diagram 1. Recall main points: Forces and FB diagrams 2. Discussion and examples

PHY 221 Ch 5: Forces and FB Diagram Forces: Gravitational Force 1. Main Points Expression: Miracle of mass (inertia) and gravitational mass: Weight: Grav force at SURFACE of EARTH

PHY 221 Ch 5: Forces and FB Diagram Forces: Empirical forces 1. Main Points Contact Forces: Normal and Tension Other Forces: Spring restoring force

PHY 221 Ch 5: Forces and FB Diagram Free Body Diagrams and example of problems 1. Main Points Box Pushed Up an Incline at constant velocity (q=30 o m=200 kg; What is the push needed? )

PHY 221 Ch 5: Forces and FB Diagram 2. Discuss Person in elevator at a. What is the reading on the scale?

PHY 221 Ch 5: Forces and FB Diagram 2. Discuss Car goes in curve of R=25 m at v=5 m/s. Find tension in string holding fuzzy die?

PHY 221 Ch 5: Forces and FB Diagram 2. Discuss Summary: Force problems • Picture: Free Body Diagram: • Identify all forces acting on m: Tension, normal, weight, others… • Draw the forces on m from origin in object: direction is usually known but mag unknown (tension, normal, etc…) • Choose axes x and y: always take un axis // acceleration if a is not zero. Otherwise (v=cst) choose axes to facilitate projection of forces on axes. • Write all vector in terms of mag, angle expressions. • Write F=ma along each axes in terms of previous result • Solve

Ch 5: Assignments

Ch 5: Assignments

Ch 5: Assignments

Ch 5: Assignments

Ch 5: Assignments

Ch 5: Assignments