The Calcylator Blog

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everyday numbers.

Practical guides, clear examples, and smarter ways to calculate.

Physics guides

22 articles

Physics5 min read
Hydrostatic Pressure at Depth: ρ × g × h Explained
At 3 m below the surface of fresh water the pressure from the liquid is 1000 × 9.81 × 3 = 29,430 Pa. Learn gauge versus absolute and the depth rule.
Physics5 min read
Kinetic Energy Formula: Why Speed Counts Twice
Kinetic energy equals ½ × mass × speed². A 1,200 kg car at 15 m/s carries 135 kJ, and doubling its speed to 30 m/s quadruples that to 540 kJ.
Physics5 min read
Mechanical Efficiency: Output ÷ Input as a Percentage
A machine that takes in 1000 W and delivers 750 W of useful output is 75% efficient, with 250 W lost as heat, noise and friction. See the formula and chains.
Physics5 min read
Mechanical Work: W = F × d × cos θ Explained
Work is force × distance × cos θ, in joules. Pushing a 20 kg load 12 m with a 30 N net force is 360 J, and a 40 N angled pull over 50 m is 1,732 J.
Physics5 min read
Momentum Formula: p = m × v With Worked Examples
Momentum is mass times velocity: a 2 kg object moving at 5 m/s carries 10 kg·m/s. See impulse, collisions and why direction needs a sign.
Physics5 min read
Gravitational Potential Energy: PE = m × g × h
Gravitational potential energy is mass × g × height: 5 kg lifted 2 m stores 98.1 J. See the formula, the choice of zero level and the Moon comparison.