Momentum is a quantity that can be thought of as a description of
"moving inertia." The faster an object is moving, the more momentum
it has. The more mass the moving object has, the more momentum it carries.
Momentum is also a way to express how much force is needed to get something
moving or to stop the object in a time of one second.
Formally, the momentum of a moving object is defined as the product of
the mass and velocity. Note that it is not just the speed, rather
the velocity. Remember, the difference between the speed and the velocity is
that velocity is a vector, it has a direction associated with it. This means
that momentum is a vector quantity. It has both a magnitude
(mass x speed) and a direction (the direction the object is moving).
The formula for momentum is:
|
p
= m v
|
where p stands for momentum, m stands
for mass (in kilograms), and v stands for velocity (in
meters/sec). This means that momentum has units of kgm/s (kilogram-meter
per second).
Example: A runner has a mass of 75 kg and is running at 6 m/s (about
13.5 mph). The runner's momentum would be:
p = m v
|
p = (75 kg)x(6 m/s)
|
p = 450 kgm/s
|
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