An 800 kg car at 20 m/s carries 160,000 J of kinetic energy (½mv²), and a 70 kg person weighs 686.5 N on Earth.
| Quantity | Formula | SI unit | Example | Result |
|---|---|---|---|---|
| Speed | v = d / t | m/s | d = 100 m, t = 10 s | 10 |
| Acceleration | a = Δv / t | m/s² | Δv = 20 m/s, t = 4 s | 5 |
| Force | F = m × a | N | m = 10 kg, a = 2 m/s² | 20 |
| Weight | Fg = m × g | N | m = 70 kg | 686.47 |
| Momentum | p = m × v | kg·m/s | m = 800 kg, v = 20 m/s | 16,000 |
| Kinetic energy | Eₖ = ½ m v² | J | m = 800 kg, v = 20 m/s | 160,000 |
| Potential energy | Eₚ = m g h | J | m = 10 kg, h = 5 m | 490.33 |
| Work | W = F × d | J | F = 50 N, d = 10 m | 500 |
| Power | P = E / t | W | E = 600 J, t = 60 s | 10 |
| Pressure | p = F / A | Pa | F = 500 N, A = 2 m² | 250 |
| Density | ρ = m / V | kg/m³ | m = 600 kg, V = 2 m³ | 300 |
| Wave speed | v = f × λ | m/s | f = 50 Hz, λ = 6 m | 300 |
| Centripetal force | F = m v² / r | N | m = 2 kg, v = 3 m/s, r = 2 m | 9 |
| Voltage (Ohm's law) | V = I × R | V | I = 2 A, R = 6 Ω | 12 |
| Electrical power | P = V × I | W | V = 120 V, I = 10 A | 1,200 |
| Frequency | f = 1 / T | Hz | T = 4 s | 0.25 |
How it is computed
Each result plugs the example values, in SI units, into the formula on its row. Weight and potential energy use standard gravity, g = 9.80665 m/s². Results are in the SI unit shown, so convert inputs to metres, kilograms and seconds first.
FAQ
What is the difference between mass and weight?+
Mass (kg) is the amount of matter and does not change. Weight is the force gravity puts on it, in newtons: m × g, about 9.81 times the mass on Earth.
Why do my results come out wrong?+
Usually mixed units. Convert km/h to m/s (divide by 3.6), grams to kilograms and minutes to seconds before using a formula.