4. At the airport, there is a moving walkway that is $500 \mathrm{~m}$ long and moves at a speed of $4 \mathrm{~km} / \mathrm{h}$. Damir and Vesna stepped onto the walkway at the same time. Vesna continued walking at a speed of 6 $\mathrm{km} / \mathrm{h}$ relative to the walkway, while Damir remained standing on it. How many meters ahead of Damir was Vesna when she stepped off the walkway?
First method:

Vesna was moving at a speed of $10 \mathrm{~km} / \mathrm{h}$ relative to the ground,

so she covered $500 \mathrm{~m}$ in $t=\frac{s}{v}=\frac{0.5}{10} \mathrm{~h}=\frac{1}{20} \mathrm{~h}$.

During this time, Damir was moving at a speed of $4 \mathrm{~km} / \mathrm{h}$ relative to the ground and covered

$s=v \cdot t=4 \cdot \frac{1}{20} \mathrm{~km}=\frac{1}{5} \mathrm{~km}=200 \mathrm{~m}$.

$500 \mathrm{~m}-200 \mathrm{~m}=300 \mathrm{~m}$

Vesna was $300 \mathrm{~m}$ ahead of Damir.

1 POINT

TOTAL 6 POINTS

##