depression definition. A period of drastic decline in the national economy, characterized by decreasing business activity, falling prices, and unemployment. The best known of such periods is the Great Depression, which occurred in the 1930s.
A variometer â also known as a rate of climb and descent indicator (RCDI), rate-of-climb indicator, vertical speed indicator (VSI), or vertical velocity indicator (VVI) â is one of the flight instruments in an aircraft used to inform the pilot of the rate of descent or climb.
Speed Conversion. Speed is defined as the rate of change in position, expressed as distance traveled per unit of time. It is a scalar quantity with dimensions distance/time. Velocity is a vector quantity, the rate at which an object changes it's position. Speed unit in SI system is meters per second (mps).