Question

Un biciclist a mers cu viteza v1=9km/h timp de 20 min, cu viteza v2=18km/h timp de 60 min, si cu viteza v3=27km/h timp de 20 min
1. Transforma mărimile in SI
2. Calculati distantele parcurse in fiecare interval de timp
3. Calculati distanta totala si timpul total
4. Calculati viteza medie pe toata distanta parcursa​
cineva rapid va rog!!.

Answer 1

Răspuns:

Explicație:

1.v₁=9km/h=9.1000m/3600s=2,5m/s

v₂=18km/h=18.1000m/3600s=5m/s

v₃=27km/h=27.1000m/3600s=7,5m/s

t₁=20minute=20.60s=1200s

t₂=60minute=60.60s=3600s

t₃=20minute=1200s

2.d₁=v₁.t₁=2,5.1200=3000m

d₂=v₂.t₂=5.3600=18000m

d₃=v₃.t₃=7,5.1200=9000m

3.d=d₁+d₂+d₃=3000+18000+9000=30000m=30km

t=t₁+t₂+t₃=1200+3600+1200=6000s

4.vm=d/t=30000/6000=5m/s