Physics 197 Lecture Notes - Lecture 5: Inertial Frame Of Reference, Net Force

• School: WUSTL
• Department: Physics
• Course: Physics 197
• Professor: Hynes

Document Summary

Newton"s second law: = = (cid:2869)+ (cid:2870)+ + = , forces cause acceleration, acceleration is a response to a force. In the absence of a net external force, an object will move in a straight line at a constant speed until a force acts on it. Includes objects at rest: valid in an inertial (non-accelerating) reference frame. Types of forces: forces are either contact forces, tension, friction, normal, drag, thrust, spring, or long-range forces, gravity and electromagnetic. Applying newton"s second law: draw forces acting on chosen object, only physical contact forces and gravity, choose inertial frame for analysis, ex: draw the forces acting on an arrow in flight. Fgravity: every force bas an equal and opposite force in reaction, equal in magnitude, opposite in direction, force pair = same force on two different objects. Conceptualizing newton"s laws: consider a car at rest.