1.
a)
[tex]3.5 \times 60 = 210min[/tex]
b)
[tex]72 \frac{km}{h} = 72 \times \frac{1000}{3600} = \frac{72000}{3600} = 20 \frac{m}{s} [/tex]
c)
[tex]35 \frac{m}{s} = 35 \times 3.6 = 126 \frac{km}{h} [/tex]
3.
V = 6km/h
s = 1500m = 1,5km
t = ?
[tex]v = \frac{s}{t} | \times t \\ s = v \times t | \div v \\ t = \frac{s}{v} [/tex]
[tex]t = \frac{1.5km}{6 \frac{km}{h} } = \frac{15}{60}h = \frac{1}{4}h = 15min[/tex]
