Answer:
D. 20.5 m/s (Works For Apex)
Step-by-step explanation:
You start with the fact that we are already at 10m/s^2 or our initial velocity is 10m/s^2. Then you add the acceleration which is 2.1 m/s^2 for 5 seconds giving us 10.5 m/s^2. 10m/s + 10.5m/s = 20.5m/s