Answer:

Explanation:
<em><u>H</u></em><em><u>o</u></em><em><u>p</u></em><em><u>e</u></em><em><u> </u></em><em><u>i</u></em><em><u>t</u></em><em><u> </u></em><em><u>h</u></em><em><u>e</u></em><em><u>l</u></em><em><u>p</u></em><em><u>s</u></em><em><u> </u></em><em><u>y</u></em><em><u>o</u></em><em><u>u</u></em><em><u> </u></em><em><u>:</u></em><em><u>)</u></em><em><u>)</u></em><em><u>)</u></em>
The dummy is moving with a speed 0 km/h relative to the seat in which it is sitting.
If the relative speed was non-zero, the dummy would move away from its seat, which contradicts the problem formulation.
That it is a good one and bad one that's what I think hope it helps!:)