Momentum is defined as the product of mass and velocity. Since velocity is a vector quantity and mass is a scalar quantity, momentum is in turn a vector quantity.
Impulse is defined as the product of the force applied
to an object and the time over which it was applied. Since
force is a vector and time is a scalar, impulse is a vector.
Since applying a force causes a net acceleration, the velocity of the object will change during the interval when the force is applied. Additionally, the units of force are kg*m/s , so the units of Ft are kg*m/s*s. These are also the units of mass*velocity. Impulse can therefore be expressed as
