Final answer:
The sprinter's radial acceleration at 3.74 s is approximately 2.03 m/s².
Step-by-step explanation:
To calculate the sprinter's radial acceleration at 3.74 s, we first need to find the speed at that time. From the given information, we know that his speed at 3.74 s is 4.5 m/s and his final speed after the curve is 12.1 m/s. The change in speed during that time is 12.1 m/s - 4.5 m/s = 7.6 m/s.
Next, we can use the formula for radial acceleration:
radial acceleration = change in speed / time
Substituting the values, we get:
radial acceleration = 7.6 m/s / 3.74 s = 2.03 m/s²
Therefore, the sprinter's radial acceleration at 3.74 s is approximately 2.03 m/s².