Odpowiedź:
s1=300m
va=5,8m/s
t1=30s
vb=2,5m/s
droga przebyta w ciągu 30s
s2=t1*va
s2=30s*5,8m/s
s2=174m
pozostała droga
s3=300m-174m=126m
ta=(s+126m)/va
ta=(s+126m)/5,8m/s
tb=s/vb
tb=s/2,5m/s
ta=tb
(s+126)/5,8=s/2,5
2,5*(s+126)=5,8s
2,5s+315=5,8s
3,3s=315
s=95,45m
t2=95,45m/2,5m/s
t2=38,1s
t=30s+38,1s
t=68,1s