In this project, this same concept was used, but applied to a human being. The output in this experiment was determined by multiplying mass, gravity, and height. The principle used to calculate this was Newton's second law of motion: force= mass * acceleration (Newton's Three Laws of Motion). Thus the experimenters realized that by varying the mass, they would directly affect the work output of the subject, because the subject would have to exert more force in order to overcome the negative acceleration of gravity. Hence for work output our calculations were: