A 2.0 kg cart rolls at 3.0 m/s. Its momentum is 6.0. Six what? A bare number is not a measurement.
Momentum needs a unit of its own. Which unit?
Momentum is mass times velocity: p = mv.
Mass carries kilograms. Velocity carries meters per second.
Multiply the quantities, and the units multiply too: kilograms times meters per second.
The SI unit of momentum is the kilogram-meter per second, written kg·m/s.
The raised dot marks the multiplication: kilogram times meter, all per second.
So the cart's momentum is written p = 6.0 kg·m/s, and a momentum of 12 kg·m/s is twice as much.
Which is the SI unit of momentum?
A 5.0 kg dog runs at 4.0 m/s. Its momentum is 20 ___. Which unit completes the value?
Every momentum value carries this unit.
A lab report states a cart's momentum as 15 kg·m/s. Is the unit correct for a momentum?
A 4.0 kg cart moves at 2.0 m/s, so p = 4.0 × 2.0 = 8.0. Write the momentum with its unit.
Mass in kilograms times velocity in meters per second gives kg·m/s.
p = 8.0 kg·m/s.
A record reads: momentum = 9.5 kg. What is wrong with the record?
kg is the unit of mass alone.
A momentum is mass times velocity, so its unit multiplies kg by m/s.
The record should read 9.5 kg·m/s.
A lab record reads: mass 2.5 kg, velocity 2.0 m/s, momentum 5.0 ___. Which unit completes the record?
Which measurement could be a momentum?
A student writes a cart's momentum as 6.5 m/s. What is wrong with the record?