A :-) for this question , we should apply
a = v - u by t
Given - u = 4.77 m/s
v = 23.5 m/s
t = 5.18 m/s
Solution -
a = v - u by t
a = 23.5 - 4.77
a = 28.27 m/s^2
.:. The acceleration is 28.27 m/s^2
For this case we have that by definition, the kinetic energy is given by the following formula:

Where:
m: It is the mass
v: It is the velocity
According to the data we have to:

Substituting the values we have:

finally, the kinetic energy is 
Answer:
Option A
Answer:
32 bottles
Explanation:
If we create a free body diagram on the child we have his weight and the bouyant force
W-B=0
They must be equal to mantain equilibrium on the body and he can stay floating, this force is equivalent to the weight of water displaced
W=B=Ww
Mg=mg
32 kg=mass of water displaced
1 kilogram per liter (kg/L) is the density of water, this means that 32 Liters of water are displaced and since the bottles can retain 1 liter, the child needs 32 bottles
The ion of idodine is neutral