PROBLEM SOLVING IN PHYSICS INTRODUCTION 1.) Read and re-read the problem. Conceptualize and understand the problem by visualizing it in your mind and drawing a diagram. 2.) What is goal of the problem? Determine the final outcome the problem is asking for and write it down. Then write down all of the given information. Make a table to list the known and unknown values/ quantities. 3.) Draw pictures. Draw as many pictures as you need and label the given and unknown information. Pictures include force diagrams, graphs, coordinate systems, conceptualize diagram, etc. 4.) Categorize the problem. Write down what con- cepts and principles are related to the problem. Write down any related formulas that may be useful in solv- ing the problem. 5.) Simplify and breakdown. Can the problem be broken down into smaller sub-problems? Write down the steps or sub-problems that you will need to solve before obtaining the final answer. 6.) Solve Algebraically. Solve each equation for the unknown variable algebraically. Use those answers to substitute into the other sub-problems if required. 7.) Complete the problem numerically. Convert all known data to equivalent units prior to substituting the values into t algebraic answers from step six. 8.) Check your answer. Does it have the correct units? Is it the right order of magnitude? Does it make sense? Does it have the correct number of sig- nificant figures? PROBLEM SOLVING DRAWING PICTURES The general goal of physics is to provide a quantitative understanding of the laws in our Universe. Problem solving within physics is the means to applying the fundamental laws of the universe to real world applications and experi- mental observations. Learning and applying problem solving techniques early in your physics career is the key to IDENTIFY CONCEPTS To help you categorize the concepts used in the prob- lem, look for keywords or code words that signal what principles and related equations apply to the problem. Word Meaning At rest, starts from rest Velocity or initial velocity is zero Constant velocity, constant speed, object at rest or doesn’t move Acceleration is zero. Net force acting on object is zero. Smooth, icy, slippery surface Friction is zero Rough, bumpy, un-even surface Friction is NOT zero Is accelerated, pushes, moves Net force acting on object is not zero. Free body diagram. Crashes, bumps, collide, bounces, impact Momentum and Impulse Free-fall, slides down, in- clined plane Acceleration due to gravity. Particle with a speed and mass Kinetic Energy, Work Rotate, spin, pulley, torque Angular and rotational kinematics Oscillation, restoring force, resonance Simple Harmonic Motion, Hooke’s Law Tension, cable, string Forces, Newton’s 2nd Law Pictures and diagrams help to understand problems in more detail. Pictures used in physics are simplified sketches. The most common form of diagrams used in physics are called Free Body Diagrams. Free body diagrams are used to break down the various forces acting on objects and show only those forces acting on the object in question. In addition, when con- structing your free body diagrams, always include your coordinate system in the picture. Free Body Diagrams