Energy, the ability or capacity to do work, is found in various forms. It can be in the form of light that is needed by plants to growth, electrical energy to light up a house, a nuclear power produced by some power plants, heat produced by the sun, or mechanical energy produced by different machines. The law of conservation of energy states that energy can neither be created nor destroyed but can only be transformed from one form to another. The transformation of energy relates to the work being done by forces that exerting on an object.
A conservative force, also called potential energy such as gravitational force and spring force, can be stored. On the other hand, a force such as friction which cannot be retrieved is called a nonconservative force. Two principal energies are kinetic energy (KE) which is involved with motion and gravitational potential energy (GPE) which pertains to position. Adding up the two energies gets the total energy of the object: E = KE + GPE = 1/2 MV2 + Mgh.
Here M, v, and h respectively indicate the mass of the object, the velocity of travel, and its height relative to some reference level. Note that Einitial = Efinal on account of the constant of total energy. If only force exerts on the object, the force does work on the object: W = F d cos (? ) (d: the magnitude of the object’s displacement,? : the angle between the force and displacement vectors). As a result, the bonding of work and energy is simplified to the work-energy theorem equation: Wnet = ?
KE. Wnet is the work done by all forces acting on the object. Since ? GPE = – Wgrav, Wnet = W + Wgrav is modified as W =? KE +? GPE= ? E. The objective of this experiment is to investigate the energy-work theorem. In this experiment, a photogate timer was used to measure the velocity of the cart which respectively attached with sliver masses or paperclips slid on the air track under the condition of gravity, external force, and both gravity and external force.
Results: Part A. The Conservation of Total Mechanical Energy In part A of the experiment, the conservation of the mechanical energy was examined. Physical measurements were made for the thickness of the aluminum block, distance between the legs of the air track, length of the cart, and the displacement of the center of the cart to the photogate timer. In addition to this, the mass of the carts were also measured.