Question

Sumit drives his car at a constant rate of 40 Km/h for one hour and then at a constant rate of
60 Km/h for one hour. Find his average speed.

Answer 1

First concert km/h into m/sec and and convert Time into seconds and then apply fourmula
Total distance travelled/Total Time taken

Answer 2

"Sumit's average speed is $50\frac { Km }{ hr }$

Solution:

We know that,

$Average\quad speed\quad =\quad \frac { Total\quad distance\quad travelled }{ total\quad timetaken }$

Given, Sumit drives the car with the "constant speed" of $40 \frac { km }{ hr }$ for one hour

After that he drives at a "constant speed" of $60\frac { km }{ hr }$ for one hour

Total distance covered by him $= 40 +60 = 100\frac { km }{ hr }$

Time taken = 1 + 1 = 2 hr

Therefore average speed $= \frac { 100 }{ 2 }$

                                       $= 50\frac { Km }{ hr }$ "