Physics 101 Chapter 6: Work & Energy Exam 100% Correct!

What is work done on an object by a constant force? - ANSWERW = F d cos θ - the product of the magnitude of the displacement times the component of the force that is parallel to the displacement - work is measured in Joules (J = N x m) What are some scenarios when no work is done? - ANSWER** You need a force & a displacement to do work 1. If you hold a heavy object in your hands at rest (the displacement of the bag = zero) 2. **When a force is perpendicular to the displacement, no work is done by that force How to solve problems dealing with work? - ANSWER1. Draw a free-body diagram 2. Choose an xy coordinate system that is convenient (usually just keep it regular) but it may help to put it in the direction of motion 3. Apply Newton's laws to determine unkown forces 4. Find the work done by a specific force on the object by using W = F d cos θ for a constant force 5. To find the net work done on the object, either (a) find the work done by each force and add the results (b) find the net force on the object and then use it to find the net work done What is energy? - ANSWERthe ability to do work What is kinetic energy vs potential energy? - ANSWER- Kinetic: energy of motion