Which has more momentum, a mouse running at 1 m/s
north or an elephant walking at 3 m/s east? Explain your
answer.

momentum of elephant will be more than the momentum of mouse

Explanation:

As we know that momentum is the product of mass and velocity

so we can write it as

here we know that a mouse is moving with speed 1 m/s

let say mass of mouse is m1 so we have

similarly now we know that elephant is moving with speed 3 m/s

now let say the mass of elephant is of mass m2 so

now we know that mass of elephant as well as speed of elephant both are more than mouse

so momentum of elephant will be more than the momentum of mouse

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement