Discuss the application of the first law of thermodynamics to a mountaineer who eats food, gets warm and perspires a lot during a climb, and does a lot of mechanical work in raising herself to the summit. The mountaineer also gets warm during the descent. Is the source of this energy the same as the source during the ascent?
when analyzing a complicated motion of a complex system it is important to consider special points of the system such as the center of mass o found by this formula: o for a system with multiple particles: o if it has multiple particles and is in 3D: vector r is the vector formed by the particles also: the center of mass of a system of particles moves as though all the system’s mass were concentrated there, and that the vector sum of all the external forces were applied there a solid body is a continuous distribution of mass, so: o the mass density is a constant: o if it is symmetrical the center of mass is at the geometric center if you take the time derivative, you
