# Which has more momentum, a 4kg object moving at 4m/s or a 5kg object moving at 9m/s?

Mar 26, 2018

Second object.

#### Explanation:

Momentum is given by the equation,

$p = m v$

• $m$ is the mass of the object in kilograms

• $v$ is the velocity of the object in meters per second

We got:

${p}_{1} = {m}_{1} {v}_{1}$

Substitute in given values,

${p}_{1} = 4 \setminus \text{kg"*4 \ "m/s}$

$= 16 \setminus \text{m/s}$

Then,

${p}_{2} = {m}_{2} {v}_{2}$

Same thing, substitute in given values,

${p}_{2} = 5 \setminus \text{kg"*9 \ "m/s}$

$= 45 \setminus \text{m/s}$

We see that ${p}_{2} > {p}_{1}$, and so the second object has more momentum than the first object.