Respostas

2014-02-18T23:54:03-03:00
Olá

vm=Δs/Δt
Δs=sf-si
Δs=68-0=0
Δt= 12:50h- 10:30=2h e 20minutos= 2+1/3 de hora= 6+1/3=7/3h=
vm=68/ 7/3h
 vm=68.3/7= 29,1 km/h