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>
Explanation:
the answers are the first 3.
Answer:
≈19.144°C.
Explanation:
all the details are in the attachment.
Note, that c₁, m₁, t₁ are the parameters of the sample of brass; c₂, m₂ and t₂ are the parameters of the sample of water.
P.S. change the provided design according Your requirements.
When the child is moving, he/she has kinetic energy. For just a brief second before they move the other way, the child is not moving, but they have gravitational potential energy.
The child may need a push from time to time because friction with the air causes loss of energy.