Oil having a density of 927 kg/m3 floats on water. A rectangular block of wood 4.12 cm high and with a density of 960 kg/m3 floats partly in the oil and partly in the water. The oil completely covers the block. How far below the interface between the two liquids is the bottom of the block? Answer in units of m.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

like poles repel so keep pushing north to north and repels funny to see this

double the distance = divide strength by 4