A car travels along a straight line for the first half time with speed 50 km/hr and the second half time with a speed 60 km/hr the average speed of the car is.

Let the total time ‘t’ hrFirst half time t/2 hrSecond half time t/2 hrDistance travelled by a car first half time,  velocity=distancetime⇒S1=v1t1=50t2=25 t km Similarly  S2=v2t2=60×t2=30 t km Average speed   =S1+S2t=25t+30tt=55tt=55 km/hrconversion:  1km=1000 meter                    1hour=60x60 secondAverage speed  =55×100060×60=15.3 m/s