Physics. Energy and Work. The Energy. We define energy the ability of a body or of a system to do work and the extent of this work is in its turn the energy measurement. Energy is an inherent, measurable property of matter belonging to the very existence of physical bodies.
Energy and Work
The physical magnitude which correlates force and displacement is called WORK.
The boxes have the same mass but they are placed at different heights relative to the floor. Boxes 1 and 2 have gravitational potential energy because when they fall they perform a work:L = m*g*h
Where k is the spring costant of the spring (see Hooke law) and x is the elongation of the spring.