Answer:
Option A. 39.2 m/s
Step-by-step explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) = 4 s
Final velocity (v) =?
v = u + gt
Since the initial velocity (u) is 0, the above equation becomes:
v = gt
Thus, inputting the value of g and t, we can obtain the value of v as shown below:
v = 9.8 × 4
v = 39.2 m/s
Therefore, the velocity of the ball at 4 s is 39.2 m/s.