A sprinter runs 100 at a speed of 7 meters per second. Then she cold down by running 100 meters at 3.5 meters per second.
To find the total time it takes for the sprinter to run 100 meters at a speed of 7 meters per second, we can use the formula:
Time = Distance / Speed
Time = 100 meters / 7 meters per second
Time = 14.29 seconds
Next, we can find the time it takes for the sprinter to cool down by running 100 meters at a speed of 3.5 meters per second:
Time = 100 meters / 3.5 meters per second
Time = 28.57 seconds
Therefore, the sprinter takes a total of 14.29 + 28.57 = 42.86 seconds to complete both the sprint and cool-down.