$\mathbf{a})$

Naszym zadaniem jest zamiana km/h na m/s. 

▶ $36\frac{\text{km}}{\text{h}}$

Wiemy, że:  

$1\text{km}=1000\text{m}$

$1\text{h = 3 600 s}$

Oznacza to, że:

$36\frac{\text{km}}{\text{h}}=36\cdot \frac{1\text{km}}{1\text{h}}=36\cdot \frac{10\cancel{00}\text{m}}{36\cancel{00}\text{s}}=$

$=\frac{360}{36}\frac{\text{m}}{\text{s}}=10\frac{\text{m}}{\text{s}}$

▶ $144\frac{\text{km}}{\text{h}}$

Wiemy, że:  

$1\text{km}=1000\text{m}$

$1\text{h = 3 600 s}$

Oznacza to, że:

$144\frac{\text{km}}{\text{h}}=144\cdot \frac{1\text{km}}{1\text{h}}=144\cdot \frac{10\cancel{00}\text{m}}{36\cancel{00}\text{s}}=$

$=\frac{1440}{36}\frac{\text{m}}{\text{s}}=40\frac{\text{m}}{\text{s}}$

▶ $1,44\frac{\text{km}}{\text{h}}$

Wiemy, że:  

$1\text{km}=1000\text{m}$

$1\text{h = 3 600 s}$

Oznacza to, że:

$1,44\frac{\text{km}}{\text{h}}=1,44\cdot \frac{1\text{km}}{1\text{h}}=$

$=1,44\cdot \frac{10\cancel{00}\text{m}}{36\cancel{00}\text{s}}=$

$=\frac{14,4}{36}\frac{\text{m}}{\text{s}}=0,4\frac{\text{m}}{\text{s}}$

 

$\mathbf{b})$

Naszym zadaniem jest zamiana m/s na km/h. 

▶ $100\frac{\text{m}}{\text{s}}$

Wiemy, że:  

$1\text{m}=\frac{1}{1000}\text{km}$

$1\text{s}=\frac{1}{3600}\text{h}$

Oznacza to, że:

$100\frac{\text{m}}{\text{s}}=100\cdot \frac{1\text{m}}{1\text{s}}=100\cdot \frac{\frac{1}{1000}\text{km}}{\frac{1}{3600}\text{h}}=$

$=100\cdot \frac{1}{10\cancel{00}}\cdot \frac{36\cancel{00}}{1}\frac{\text{km}}{\text{h}}=\frac{360\cancel{0}}{1\cancel{0}}\frac{\text{km}}{\text{h}}=$

$=360\frac{\text{km}}{\text{h}}$

▶ $50\frac{\text{m}}{\text{s}}$

Wiemy, że:  

$1\text{m}=\frac{1}{1000}\text{km}$

$1\text{s}=\frac{1}{3600}\text{h}$

Oznacza to, że:

$50\frac{\text{m}}{\text{s}}=50\cdot \frac{1\text{m}}{1\text{s}}=50\cdot \frac{\frac{1}{1000}\text{km}}{\frac{1}{3600}\text{h}}=$

$=50\cdot \frac{1}{10\cancel{00}}\cdot \frac{36\cancel{00}}{1}\frac{\text{km}}{\text{h}}=\frac{180\cancel{0}}{1\cancel{0}}\frac{\text{km}}{\text{h}}=$

$=180\frac{\text{km}}{\text{h}}$

▶ $2\frac{\text{m}}{\text{s}}$

Wiemy, że:  

$1\text{m}=\frac{1}{1000}\text{km}$

$1\text{s}=\frac{1}{3600}\text{h}$

Oznacza to, że:

$2\frac{\text{m}}{\text{s}}=2\cdot \frac{1\text{m}}{1\text{s}}=2\cdot \frac{\frac{1}{1000}\text{km}}{\frac{1}{3600}\text{h}}=$

$=2\cdot \frac{1}{10\cancel{00}}\cdot \frac{36\cancel{00}}{1}\frac{\text{km}}{\text{h}}=\frac{72}{10}\frac{\text{km}}{\text{h}}=$

$=7,2\frac{\text{km}}{\text{h}}$