-, electrical, or other forms. According to the law of conservation of energy, the total energy of a system remains constant, though energy may transform into another form. The SI unit of energy is the joule (J) or newton-meter (N * m).

t. The principle of density was discovered by the Greek scientist Archimedes. To calculate the density (usually represented by the Greek letter "rho") of an object, take the mass (m) and divide by the volume (v): rho = m / vto calculate the value automatically - which is why you can get on a scale and have read your mass. The SI unit of mass is the kilogram (kg). magnetic fluxh charge and radially in toward a negative point charge. Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes.

magnetic lines of force----Curved lines used to represent a magnetic field, drawn such that the number of lines is related to the strength of the magnetic field at a given point and the tangent of any curve at a particular point is along the direction of magnetic force at that point.

A 'unit' is exactly equivalent to one kilowatt hour, and is used in Britain as the unit of measurement for purchasing electrical energy.The horsepower (hp) is a unit in the foot-pound-second ( fps ) or English system, sometimes used to express the rate at which mechanical energy is expended. It was originally defined as 550 foot-pounds per second (ft-lb/s).A power level of 1 hp is approximately equivalent to 746 watt s (W) or 0.746 kilowatt s (kW).