Question

Jerome plays middle linebacker for souths varsity football team. In a game against cross-town rival north, he delivered a hit to north’s 82-kg running back, changing his eastward velocity of 5.6 m/s into a westward velocity of 2.5 m/s. Determine that momentum change of the running back

Answer 1

The change in momentum is 664.2 kgm/s in the westward direction.

Step-by-step explanation:

Considering eastward direction as positive and westward direction as negative.

Given:

Mass of the running back is,
`m=82\ kg`

Initial velocity of the running back is,
`u=5.6\ m/s`

Final velocity of the running back is,
`v=-2.5\ m/s`

Now, we know that, momentum is given as the product of mass and velocity.

So, initial momentum of the running back is given as:

`p_i=mu=82* 5.6=459.2\ kgms^(-1)`

Final momentum of the running back is given as:

`p_f=mv=82* -2.5=-205\ kgms^(-1)`

Now, change in momentum is given as the difference of final momentum and initial momentum.

Change in momentum = Final momentum - Initial momentum

⇒
`\Delta p=p_f-p_i`

⇒
`\Delta p=-205 - 459.2 = -664.2\ kgms^(-1)`

Therefore, the change in momentum is 664.2 kgm/s in the westward direction as the value is negative.