Respuesta :

Answer:

   a = 8.4 m / s²

Explanation:

The mean acceleration is defined by

          a = (v_f- v₀) / (t_f - t₀)

where v are the final and initial velocities, respectively and t is the time interval

Let's apply this equation to our case

the final velocity is 99 m / s and the initial velocity is 57 m / s

         a = (99 - 57) / (15 - 10)

         a = 8.4 m / s²