Geologists place tiltmeters on the sides of volcanoes to measure the displacement of the surface as magma moves inside the volcano. Although most tiltmeters today are electronic, the traditional tiltmeter, used for decades, consisted of two or more water-filled metal cans placed some distance apart and connected by a hose. The figure(Figure 1) shows two such cans, each having a window to measure the water height. Suppose the cans are placed so that the water level in both is initially at the 5.0cm mark. A week later, the water level in can 2 is at the 6.6cm mark. Cans are 100m apart.

Question

Q: Did can 2 move up or down relative to can 1?
A: Can 2 has moved down

Q: By what distance??????

Q: Where is the water level now in can 1?????

Answer 1

distance, it moved down 1 cm
in can 1, the water level is at 4cm

Answer 2

How exactly do you get those answers? Also, the program says those are not the right answers.