The arms of a vertical U tube of uniform inner cross section contains mercury. In one of the arms of the tube, water column of length 8 cm is introduced. In the other arm, oil of density 0.75 g/cm`""^(3)` is poured till the upper surfaces of water and oil are at same horizontal level. Calculate the length of oilcolumn.

Explanation

To solve the problem, we need to establish the relationship between the heights of the columns of water, oil, and mercury in the U-tube. Let's break it down step by step.

### Step 1: Understand the Setup
We have a U-tube with mercury, water, and oil. The water column has a height of 8 cm, and the oil has a density of 0.75 g/cm³. The heights of the mercury in both arms of the U-tube will adjust until the pressure at the same horizontal level is equal.

### Step 2: Establish the Pressure Balance
At the same horizontal level in both arms, the pressure exerted by the water column and the oil column plus the mercury column must be equal.

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