Odpowiedź:
Wyjaśnienie:
t1=10min=600s
v1=45km/h=45000m /3600s =12,5m/s
t2=20min=1200s
v2=70km/h=70000m /3600s =19,4m/s
t3=15min=900s
s3=12km=12000m
Oblicz vśr
vśr =cała droga /czas
vśr =s/t
Obliczam drogi
s1=v1*t1
s1=12,5 m/s *600s
s1=7500m
s2=v2*t2
s2=19,4m/s *1200s
s2=23280m
cała droga
s=s1+s2+s3
s=7500m+23280m +12000m=42780m
cały czas
t=t1+t2+t3
t=600s+1200s+900s
t=2700s
vśr =42780m/2700s
vśr =15,8m/s
