# Which has more momentum, a "3 kg" object moving at "2 m/s" or a "5 kg" object moving at "9 m/s"?

Dec 18, 2015

Well, this is just evaluating your ability to remember the momentum equation:

$p = m v$
where $p$ is momentum, $m$ is mass in $\text{kg}$, and $v$ is velocity in $\text{m/s}$.

So, plug and chug.

${p}_{1} = {m}_{1} {v}_{1} = \left(3\right) \left(2\right) = \text{6 kg"*"m/s}$

${p}_{2} = {m}_{2} {v}_{2} = \left(5\right) \left(9\right) = \text{45 kg"*"m/s}$

CHALLENGE: What if these two objects were cars with well-lubricated wheels on a frictionless surface, and they collided head-on in a perfectly elastic collision? Which one would move in which direction?