Momentum calculator

Momentum is mass times speed: p = m v. A 70 kg walker at 1.4 m/s (about 5 km/h) has 98 kg·m/s. A 1400 kg car at 13.9 m/s, about 50 km/h, has 19,460 kg·m/s, the 19,500 order on the page. A rider plus bike at 85 kg and 6.9 m/s (about 25 km/h) has about 587 kg·m/s. A bike at 80 kg and 8 m/s is 640 kg·m/s. A 0.43 kg ball at 30 m/s is 12.9 kg·m/s. A 0.06 kg ball at 55 m/s is 3.3 kg·m/s.

A 40,000 kg rig at 22.2 m/s (about 80 km/h) is 888,000 kg·m/s. A 2,000,000 kg consist at 16.7 m/s (about 60 km/h) is 33,400,000 kg·m/s. A 75 kg skater at 12 m/s is 900 kg·m/s. That is why a train takes long to stop and a bike does not: larger m v is harder to change. Twice the v at the same mass is twice the p, but four times Ek, because Ek = ½ m v².

Mass is in kilograms, speed in m/s on the label. The result is in kg·m/s. 50 in an m/s field is 180 km/h, not fifty on the speedo. 72 km/h is 20 m/s. Type 50 km/h as 13.9. A comma and a period are the same v: 1,4 and 1.4. Typed 0 kg or 0 m/s gives p = 0. Both fields need a number before 98 can appear. Momentum is a vector: direction matters when you add momenta. This calculator computes the value m v.

Change of momentum lives on impulse: J = F Δt = Δp. 1000 kg from 20 m/s to rest is 20,000 kg·m/s. Stopping distance and decelerated motion give s and t, not momentum. Here the product stands alone.

The US switch may show pounds on the mass label, but you still want v in m/s from the label. Convert 50 km/h to 13.9 before you type v. The header symbol does not push momentum.

Type 70 and 1.4, click Calculate, and match 98 kg·m/s. Then 1400 and 13.9. Treat 19,500 as the order of a car at 50 km/h, not as energy in joules.