Enter a latitude, a day of the year and the sunrise and sunset times you read off a clock, and the page works out the day length, the solar noon, how high the sun actually gets at noon, and the solar declination behind all of it. Each number is checked against the NOAA solar-position series rather than a lookup table.
Size a rain tank from a monthly mass balance of catchment, rainfall, runoff coefficient and household demand, with days of autonomy.
Mass to moles to STP volume for any compound, plus M, mM, mol/L, g/L, mg/mL and ppm, with the molar mass table shown.
Acoustic Doppler for a moving source and observer, and the relativistic longitudinal factor for light, kept strictly apart.
Wien's peak wavelength and the Stefan-Boltzmann flux, with the luminosity of a star at the radius you type.
Water intake, urine volume, urinary calcium and urinary oxalate scored 0-100 with each factor's points and the arithmetic shown, so you can see which input moved the number. An educational estimate, not medical advice.
Compound gear train from teeth counts: output rpm, overall ratio, torque after a stated efficiency, and the service factor load.
Sound pressure level, intensity addition of independent sources, and inverse-distance falloff, with the arithmetic shown.
Critical angle from static friction, then the slide or hold verdict, acceleration down the ramp and the work done against friction.
