It took Joash 20 minutes 11 seconds to complete an activity. How long did he take in seconds?

$$1200 \text{ sekunde} + 11 \text{ sekunde} = 1211 \text{ sekunde}$$

Joash alitumia muda wa sekunde 1211.

Swali la 4:
Ili kubadilisha sekunde kuwa masaa, tunagawanya idadi ya sekunde kwa 3600 (kwa sababu saa 1 ina dakika 60, na kila dakika ina sekunde 60, hivyo $60 \times 60 = 3600$ sekunde).

a) 7200 sekunde

$$\frac{7200 \text{ sekunde}}{3600 \frac{\text{sekunde}}{\text{saa}}} = 2 \text{ saa}$$

Muda ni 2 saa.

b) 10800 sekunde

$$\frac{10800 \text{ sekunde}}{3600 \frac{\text{sekunde}}{\text{saa}}} = 3 \text{ saa}$$

Muda ni 3 saa.

c) 21600 sekunde

$$\frac{21600 \text{ sekunde}}{3600 \frac{\text{sekunde}}{\text{saa}}} = 6 \text{ saa}$$

Muda ni 6 saa.

Swali la 5:
Ili kubadilisha masaa kuwa dakika, tunazidisha idadi ya masaa kwa 60 (kwa sababu saa 1 ina dakika 60).

$$\frac{8}{3} \text{ saa} \times 60 \frac{\text{dakika}}{\text{saa}} = 8 \times \frac{60}{3} \text{ dakika} = 8 \times 20 \text{ dakika} = 160 \text{ dakika}$$

Sointa alitumia muda wa dakika 160.

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WEDNESDAY

Swali la 1:
Ili kubadilisha kilomita kwa saa (km/h) kuwa mita kwa sekunde (m/s), tunatumia uwiano wa ubadilishaji:
$1 \text{ km} = 1000 \text{ m}$
$1 \text{ saa} = 3600 \text{ sekunde}$
Hivyo, $1 \frac{\text{km}}{\text{h}} = \frac{1000 \text{ m}}{3600 \text{ s}} = \frac{5}{18} \frac{\text{m}}{\text{s}}$.

a) 9km/h

$$\frac{45}{18} \frac{\text{m}}{\text{s}} = \frac{5}{2} \frac{\text{m}}{\text{s}} = 2.5 \frac{\text{m}}{\text{s}}$$

Kasi ni $\boxed{2.5 \frac{\text{m}}{\text{s}}}$.

b) 60km/h

$$\frac{300}{18} \frac{\text{m}}{\text{s}} = \frac{50}{3} \frac{\text{m}}{\text{s}} \approx 16.67 \frac{\text{m}}{\text{s}}$$

Kasi ni $\boxed{16.67 \frac{\text{m}}{\text{s}}}$.

c) 27km/h

$$\frac{135}{18} \frac{\text{m}}{\text{s}} = \frac{15}{2} \frac{\text{m}}{\text{s}} = 7.5 \frac{\text{m}}{\text{s}}$$

Kasi ni $\boxed{7.5 \frac{\text{m}}{\text{s}}}$.

d) 54 km
Kumbuka: Swali hili linaonekana kuwa na makosa ya uchapaji kwani "54 km" ni umbali, si kasi. Ili kuibadilisha kuwa mita kwa sekunde, inapaswa kuwa "54 km/h". Nitachukulia kuwa inapaswa kuwa 54 km/h.

$$\frac{270}{18} \frac{\text{m}}{\text{s}} = 15 \frac{\text{m}}{\text{s}}$$

Kasi ni $\boxed{15 \frac{\text{m}}{\text{s}}}$.