To solve this exercise it is necessary to take into account the concepts related to thermal expansion.
The thermal expansion is given by the function,

Where,
Change in Length
Change in Temperature
Coeficiente de dilatación lineal
Initial Length
By quickly deducing the formula, we can realize that the greater the change in temperature, the greater the change in the length of the radius.
The change in length is proportional to the change in temperature. Considering that the other two terms are constant we have that the correct one would be: <em>The hole in the center of the washer will expand.</em>
Answer:
= +3,394 103 m / s
Explanation:
We will solve this problem with the concept of the moment. Let's start by defining the system that is formed by the complete rocket before and after the explosions, bone with the two stages, for this system the moment is conserved.
The data they give is the mass of the first stage m1 = 2100 kg, the mass of the second stage m2 = 1160 kg and its final velocity v2f = +5940 m / s and the speed of the rocket before the explosion vo = +4300 m / s
The moment before the explosion
p₀ = (m₁ + m₂) v₀
After the explosion
pf = m₁
+ m₂ 
p₀ = [texpv_{f}[/tex]
(m₁ + m₂) v₀ = m₁
+ m₂
Let's calculate the final speed (v1f) of the first stage
= ((m₁ + m₂) v₀ - m₂
) / m₁
= ((2100 +1160) 4300 - 1160 5940) / 2100
= (14,018 10 6 - 6,890 106) / 2100
= 7,128 106/2100
= +3,394 103 m / s
come the same direction of the final stage, but more slowly
This would be a physical change because it can change back to its original form. This is like ripping paper. You can piece it back together and it still is paper.
The opposite of this is chemical change. Chemical change means the product has been changed completely like burning paper. The paper has now been turned to ash and it's impossible to change this back to its original form.
I’m not sure sorry I really wish I could help