Geologists place tiltmeters on the sides of volcanoes to measure the displacement of the surface as magma

Question:

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. FIGURE P14.45 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 5.0 cm mark. A week later, the water level in can 2 is at the 6.5 cm mark.
a. Did can 2 move up or down relative to can 1? By what distance?
b. Where is the water level now in can 1?

FIGURE P14.45 100 m