Conservation of Mechanical Energy
In this section, we examine what happens to this mechanical energy when only conservative forces cause energy transfers within the system-that is, when frictional
and forces do not act on the objects in the system.
In an isolated system where only conservative forces cause energy changes, the kinetic energy and potential energy can change, but their sum, the mechanical energy Ernest of the system, cannot change.
This result is called the principle of conservation of mechanical energy. (Now you can see where conservative forces got their name.) With the aid of we can write this principle in one more form.
When mechanical energy of a system is conserved, we can relate the sum of kinetic energy and potential.
CHECKPOINT 3: The figure shows four situations-one in which an initially stationary block is dropped and three in which the block is allowed to slide down friction less ramps. ·(a) the situations according to the kinetic energy of the block at point B, greatest first. (b) Rank them according to the speed of the block at point B, greatest.