heittosuhde

Heittosuhde is a Finnish term meaning throw ratio, used to describe the relationship between the input that drives a throw and the resulting output (distance, height, or velocity) of the throw. The term is not tied to a single discipline; its exact definition and measurement depend on the context, but it generally expresses how efficiently an energy, force, or mechanism converts input into a projection.

Common domains include sports science, where coaches analyze how technique, arm speed, and leg drive affect release velocity and range; engineering and robotics, where launchers, catapults, or payload-slinging mechanisms are characterized by the transfer efficiency from actuator input to projectile motion; and ballistics, where muzzle energy or launch velocity is related to propellant charge.

Measurement and calculation: One can define heittosuhde as the ratio output quantity to input quantity. In projectile motion with variable launch angle θ and initial speed v0, the ideal throw distance is d = v0^2 sin(2θ) / g. A simple input-output coefficient could be C = d / v0^2, which equals sin(2θ)/g for a fixed g. In practice, air resistance, spin, and limits of the mechanism alter the relationship, so the coefficient is empirical.

Applications and interpretation: A higher heittosuhde indicates more distance per unit of input energy, other factors equal. It is used to compare techniques, configurations, or equipment, or to optimize settings. See also: projectile motion, launch velocity, release angle.