A solid is completely immersed in a liquid. The force exerted by the liquid on the solid will

Options

A. increase if it is pushed deeper inside the liquid
B. change if its orientation is changed
C. decrese if it is taken partially out of the liquid
D. be in the vertially upward direction

Answer

To solve the question regarding the force exerted by a liquid on a solid that is completely immersed, we can follow these steps:

### Step 1: Understand the Concept of Buoyancy
When a solid is completely immersed in a liquid, it displaces a volume of liquid equal to its own volume. This displacement creates an upward force known as the buoyant force (Fb).

**Hint:** Recall Archimedes' principle, which states that the buoyant force is equal to the weight of the liquid displaced by the solid.

### Step 2: Determine the Direction of the Buoyant Force
The buoyant force acts in the vertically upward direction. This is due to the pressure difference between the top and bottom of the solid when it is submerged.

**Hint:** Visualize the pressure acting on different parts of the solid; the pressure at the bottom is greater than at the top, resulting in an upward force.

### Step 3: Analyze the Effect of Depth
If the solid is pushed deeper into the liquid, the volume of liquid displaced does not change, as the solid is still completely submerged. Therefore, the buoyant force remains constant.

**Hint:** Consider that the density of the liquid and gravitational acceleration are constant throughout the depth for incompressible fluids.

### Step 4: Analyze the Effect of Orientation
Changing the orientation of the solid does not affect the volume of liquid displaced, as long as the solid remains fully submerged. Thus, the buoyant force remains unchanged.

**Hint:** Think about how the shape of the solid might change the orientation but not the volume submerged.

### Step 5: Analyze the Effect of Partial Immersion
If the solid is partially taken out of the liquid, the volume of liquid displaced decreases. Consequently, the buoyant force will also decrease since it is directly proportional to the volume of liquid displaced.

**Hint:** Visualize the solid being pulled out and note how the volume submerged changes.

### Conclusion
Based on the analysis:
- The force exerted by the liquid on the solid will act in the vertically upward direction (Option 4 is correct).
- The force will not increase if pushed deeper (Option 1 is incorrect).
- The force will not change if the orientation is changed (Option 2 is incorrect).
- The force will decrease if the solid is partially taken out of the liquid (Option 3 is correct).

Thus, the correct options are 3 and 4.