posted by presalie .
a cyclist travels at a distance of 10.0 km. in 30 min. after w/c he speeds up to 40 km/hr for 6.0 more mins. Find his average speed.
d1 = 10km.
d2 = 40km/hr * (6/60)hr = 4km.
Vavg = (di + d2) / (t1 + t2),
Vavg=(10 + 4) / (0.5 + 0.1)=23.3km/hr.