Zamień jednostki: 20m/min= m/s 50km/h= m/s 900m/min= m/s 18km/s= km/h

[latex]20frac{m}{min} = 20cdotfrac{m}{60s} = 0,(3)frac{m}{s}approx0,33frac{m}{s}\\50frac{km}{h} = 50cdotfrac{1000m}{3600s} = 13,(8)frac{m}{s}approx13,89frac{m}{s}\\900frac{m}{min} = 900cdotfrac{m}{60s} = 15frac{m}{s}\\18frac{km}{s} = 18cdotfrac{km}{frac{1}{3600}h}=18cdot3600frac{km}{h} = 64 800frac{km}{h}[/latex]