Arm and leg weakness can be caused by a variety of different conditions, some of them temporary and others chronic. Excessive exercise is one cause of temporary fatigue in the major muscle groups, although this is not considered true muscle weakness.
Mass is an intrinsic property of the body and gravity is the force exerted on any body by the things that surround it. Weight, on the other hâ¦and, depends on gravity. It is equal to the product of the mass of the body and the gravitational force acting on it.
In physics, mass is a property of a physical body. It is the measure of an object's resistance to acceleration (a change in its state of motion) when a net force is applied. It also determines the strength of its mutual gravitational attraction to other bodies. The basic SI unit of mass is the kilogram (kg).