v₀ = initial speed of the blood = 0
![(m)/(s)](https://img.qammunity.org/2020/formulas/physics/middle-school/5mfyjokzpoi5z4ddarj96ajjnw86dluvzn.png)
v = final speed of the blood = 0.76
![(m)/(s)](https://img.qammunity.org/2020/formulas/physics/middle-school/5mfyjokzpoi5z4ddarj96ajjnw86dluvzn.png)
a = average acceleration of red blood cell
t = time of contraction = 250 ms = 0.250 s since 1 ms = 0.001 s
Using the equation
v = v₀ + a t
inserting the values
0.76 = 0 + a (0.250)
a = 3.04
![(m)/(s^(2))](https://img.qammunity.org/2020/formulas/physics/high-school/e5ya376coby7tmfzxr8i4iaj35mhkxrulr.png)