Calculate acceleration of an object moving from a stop to 21 m/s in 3.9 s

Heya!!

For calculate aceleration, lets applicate formula:

                                                   Δ   Being   Δ

                                          V = Final Velocity = 21 m/s

                                         Vo = Initial Velocity = 0 m/s

                                          a = Aceleration =  ? m/s²

                                                  t = Time = 3,9 s

⇒ Let's replace according the formula:

⇒ Resolving

Result:

The aceleration of the object is 5,38 m/s²

Good Luck!!

answer///scientific method;