Basic Physical Definitions

Kinetic energy is the amount of work an object with a mass of m moving at a speed of v can perform while its speed is reduced to zero: E_k = 1/2 mv^2. The unit of kinetic energy is joule.

Electron volt is a unit of energy. It is equivalent to the amount of kinetic energy gained by a single electron when accelerated through a voltage difference of 1 V.

Force is a vector quantity characterizing the capability to cause acceleration.

Acceleration is the rate of velocity change with time: a = dv/dt, where a is acceleration, dv is the change in velocity in time t.

The acceleration of an object (a) is given by the ratio of the net (or resultant) force acting upon it (Fn) and the mass of the object (m): a = Fn/m.

Centripetal acceleration (ac) is the rate of change in the direction of velocity with time.