The solid, liquid and gas phases of water would have the same structure of the molecules since they are same substance. The only difference would be the distances of the molecules in the container. For a ice, the molecules are close to each other where the molecules vibrate only in place. For liquid, the molecules are freely moving and are at some distance with each other but not that far away with each other. Steam, on the other hand, would have molecules that are very far from each other and are freely moving in the whole container. As the container is heated, the size of the molecules would not change. It is only the volume that has changed. Also, the mass is the same since there is no outflow of the substances.
Answer:

Explanation:
As we know that box is initially at rest
So we will have

now as it will be displaced from initial position to final position then final speed of the box is reached to

now we know by work energy theorem that work done by all the forces on the box will be equal to the change in kinetic energy
So here we will have



Answer:
The diameter of the moon's image is 0.31 cm.
Explanation:
Given that,
Focal length = 34.3 cm
Diameter of the moon 
Mean distance from the earth 
At that distance the object is assumes to be at infinity. hence the image will be formed at a distance equal to focal length
So, the image distance is 34.3 cm.
We need to calculate the diameter of the moon's image
Using formula of magnification




Hence, The diameter of the moon's image is 0.31 cm.