Question

A train moving at a constant velocity of54kmph moves east wards for 30min ,then due north with the same speed for 40 min what is average velocity of train during this run??

Answer 1

distance covered due east= 54km/hr * 1/2 hr=27 km 
distance covered due north=54km/hr * 4/6hr=36 km
displacement is the hypotenuse between starting and initial point.
=√27² + 36² = 45km
total time= 70 mins or 7/6 hrs
avg velocity=total displaceent/time=45*6/7=38.4 km/hr
so ∴ avg velocity is 38.4 km/hr.