[tex]3.5h \times 3600s = 12600s[/tex]
[tex]15 \frac{m}{s} = 15 \times 3.6 = 54 \frac{km}{h} [/tex]
[tex]120 \frac{km}{h} = 120 \times \frac{1000}{3600} = 1 \times \frac{1000}{30} \approx33 \frac{m}{s} [/tex]
[tex]2.5 \frac{km}{h} = 2.5 \times \frac{1000}{3600} = \frac{2500}{3600} \approx0.69 \frac{m}{s} [/tex]
