Velocity Is Velocity Averaged Over

¶ … velocity is velocity averaged over a given period of time, represented as change in distance divided by time. Instantaneous velocity is the limit of the average velocity as time tends to zero, or more simply put, the average velocity over an infinitesimally small period of time. Acceleration is the rate of change of velocity. (Winnipeg)

Scalar values represent magnitude only, and can be used across different coordinate systems. Mass is a scalar quantity - for example, 1kg. Vectors include both magnitude and direction. Force is a vector quantity - for example, a 1kg rock on Earth is being pulled by gravity with a force of about 10N toward the center of the Earth.

Position is the product of velocity and time. Velocity is the product of acceleration and time.

A vt at The magnitude of frictional force is the product of the force pushing two objects together and the coefficient of friction between the two objects. The coefficient of friction cannot be calculated without the aid of a complex computer simulation. It is normally determined experimentally. The coefficient of sliding friction between two objects is determined by measuring the acceleration experienced one of the objects while sliding across the other with all other forces acting on it in a state of equilibrium The coefficient of static friction between two objects is determined by applying force to one of the objects while it is stationary, and measuring the force required before the object begins sliding. The magnitude of the gravitational force between two objects is the product of the masses of each object divided by the square of the distance between them.

In order to perform calculations on a projectile, orbiting body or other object that is not moving linearally, it is convenient to split up its motion and/or forces in to component vectors. Component vectors are the portions of the vectors that line up with the coordinate system. For example, an arrow fired upward and north at a velocity of 4m/s has a velocity of 2m/s up and 2m/s north according to the Pythagorean theorem. The theorem can again be used to re-integrate the component vectors in to the actual vector after performing calculations. (Koehler)

Centripetal force is the force required to maintain its speed while moving in a circle. An object moving in a straight line will continue to do so unless acted upon by an outside force. The centripetal force can be supplied by a number of sources, including electromagnetic attraction and the gravitational force between a satelite and its primary. Centripetal force is often confused with centrifugal force, which is not a real force, but the apparent force caused by inertia while an object is changing direction.

Static equillibrium is maintained when the sum of all the forces acting on a stationary object is zero.

Mechanical energy is most commonly transformed in to electrical energy by means of moving a magnet over a conductor. Modern electrical generators use either a spinning magnet inside a torrodial coil of conductive wire, or a spinning torroidal coil of conductive wire with a stationary magnet inside. The energy can then be transmitted along any conductor connected to the coil.

In a direct current circuit, the potential difference across the circuit is reduced by the product of the resistance and the square of the product of the current and the potential difference applied to it. (Stollery)