11-1 Work and energy Example: If a person pulls an object uphill. After some time, he becomes tired and stops We can analyze the forces exerted in this problem based on Newtons Laws, but those laws can not explain: why the man's ability to exert a force to move forward becomes used up For this analysis, we must introduce the new concepts of Work and Energy ch 11 Energy I: Work and kinetic energyCh.11 Energy I: Work and kinetic energy 11-1 Work and energy Example: If a person pulls an object uphill. After some time, he becomes tired and stops. We can analyze the forces exerted in this problem based on Newton’s Laws, but those laws can not explain: why the man’s ability to exert a force to move forward becomes used up. For this analysis, we must introduce the new concepts of “Work and Energy