Rule of 70 ( estimating the time for money's buying power to halve)
Heat flow in electronics - maximum power dissipate
Motor Torque constant - with velocity constant
Rotational energy
One-repetition maximum (Brzycki formula)
Simplified von Mises equation - Pure shear
Vis-Viva Equation with standard gravitational parameter
Richter magnitude scale
Stress in thin-walled pressure spherical vessels
Reynolds number (for a flow in a tube)