Articles

A darts checkout takes your score to exactly zero on a double. Learn the double-out rule, why 170 is the top finish, and which bogey numbers cannot be done.

A 1 kg spool of 1.75 mm PLA holds about 335 metres. Learn how weight, density and diameter set filament length, and how to check what is left.

A 10-hour audiobook at 1.5x takes 6 hours 40 minutes. See the time saved at every speed, how fast narrators talk, and what research says about understanding.

Work out how much epoxy a pour needs, then split it into resin and hardener. See 1:1, 2:1, 3:1 and 4:1 splits, weight vs volume, and safety basics.

Wood weight is volume times density. See dry weight per cubic foot for 9 species, green vs dry wood, and how to turn board feet into pounds.

Learn what GPM, L/min, m3/h and CFM mean, how to convert between them, and how to use a flow rate to work out how long a tank takes to fill.

Mach number is speed divided by the local speed of sound. See Mach 1 at different temperatures, the flight regimes, and the isentropic ratios at Mach 2.

Convert RPM to radians per second with one factor, 2 pi / 60. See a conversion chart, degrees per second, linear speed and power from torque.

One g equals 9.80665 m/s^2. Learn how to convert any acceleration to g, what 0-60 mph times mean in g, and why astronauts feel 3 g and 0 g.

One pound-force equals 4.448 newtons. Learn what a newton is, how lbf and kgf are defined, why a pound of mass is not a pound-force, and how to convert.