Question

A cyclist rides his cycle with a speed of 30m/s for the first half and the next half-length he covers with a speed of 45m/s.find the average speed of the cyclist

Answer 1

av.speed =total distance/total time let total distance is x and in first half(x/2) speed is 30m/s so time in first half t1=x/2×30 and another next half (x/2) speed is 45m/s so time in next half is t2=x/2×45 so av. speed=x/t1+t2 , av.speed =x/x/2(1/30+45) and x and x cancelled out then av.speed =2/45+30/1350 ,,, av.speed =2×1350/75

after solving it av.speed is 36 m/sec