Momentum

Momentum is a measure of how difficult it is to stop an object.

It takes into account both the:

• mass of the object (how much matter it contains)
• velocity of the object (how fast it’s moving)

In a way, it’s similar to inertia, though inertia only takes into account the mass of the object, not also the velocity.

Units

Momentum is measured in kilogram meters per second (kgms^{-1}).

Calculating momentum

We know because of the units, we can calculate momentum using the following equation:

\text{momentum} = \text{mass} \times \text{velocity}

p = mv

Where:

• p is the momentum in kilogram meters per second (kgms^{-1})
• m is the mass of the object in kilograms (kg)
• v is the velocity of the object in meters per second (ms^{-1})

Stopping an object

The greater the momentum of an object, the more difficult it is to stop it.