To find the average speed for the whole race, you just have
to add the speed from a starting marker and the speed from the turnaround
marker going back and divide it by 2 since there are only two speeds involved.
10 m/s + 16m/s = 26 m/s / 2 = 13 m/s
Therefore, the average speed for the whole race is 13 m/s.
<span>Average speed = Total Distance/Total time ------(1)
Let us assume that the distance from starting marker to turnaround marker is 'x'
Total distance travelled = 2x
Speed from starting marker to turnaround marker , s1 = 10 m/s
Speed from turnaround market to starting market , s2 - 16 m/s
Let,
Time taken from starting marker to turnaround marker be t1
Time taken from turnaround marker to starting marker be t2.
Applying these values in equation (1),
Average speed = (2x)/(t1+t2) -------(2)
From (1), t1 = x/s1 = x/10
t2 = x/s2 = x/16
Substituting the above in (2),
Average speed = (2x)/(x/10+x/16) m/s
= (2x)/(13x/80) m/s
= 160/13 m/s
= 12.3 m/s
We can also arrive at the average speed by using the formula 2(s1)(s2)/(s1+s2)</span>
