Physics units are used to measure physical quantities such as force, energy, and radiation. RADS is a unit of absorbed radiation dose, equal to an energy of 100 ergs per gram of irradiated material. ERGS is a unit of energy, equal to the work done by a force of one dyne acting over a distance of one centimeter. DYNES is a unit of force, equal to the force required to accelerate a mass of one gram at a rate of one centimeter per second squared.