Question

The position-time graph represents two walkers traveling in a constant direction. Which walker has a slower average velocity? Which aspects of the graph represents average velocity?

Raul:the y-intercepts represent their average velocities.
Kin:the y-intercepts represent their average velocities.
Raul: the slopes represent their average velocities.
Kin: the slopes represent their average velocities.

Answer 1

Average velocity = Total displacement/total time taken for that amount of displacement

See the two curves,both have covered the same amount of displacement,but Kin has done it taking more time than Raul.

So, we can say, average velocity of Raul(`v`) = `x/(t1)` and for Kin(`v'`)= `x/(t2)`

As, `t2>t1` , so `v>v'`

So, Kin has slower average velocity.

Answer 2

The graph for Kin is not as steep as the graph for Raul.
Raul is walking at a higher velocity.

Explanation:

Looking at the graphs you can see that Raul took about `1½` hours to walk `6` km, while Kin took about `2 ½` hours to walk `6` km. This means that Kin is walking slower.

You can see this immediately from the slopes. The slope represents the change in distance (vertical axis) compared to the change in time (horizontal axis).

A steeper slope (Raul) indicates a higher velocity and a gentler slope (Kin) indicates a slower velocity.

The fact that Kin started walking after Raul does not affect the velocity.