A block of wood weighs 4N in air and 3N when immersed in a liquid The buoyant force on wooden block is

Options

A. zero
B. 1
C. (3/4)
D. (4/3)

Answer

To find the buoyant force acting on the wooden block, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Weight of the Block in Air**:
The weight of the wooden block when it is in air is given as 4 N. This is the actual weight of the block (W_air).

\[ W_{\text{air}} = 4 \, \text{N} \]

2. **Identify the Weight of the Block in Liquid**:
The weight of the wooden block when it is immersed in the liquid is given as 3 N. This is the apparent weight of the block when submerged (W_liquid).

\[ W_{\text{liquid}} = 3 \, \text{N} \]

3. **Understand the Concept of Buoyant Force**:
The buoyant force (B) acting on the block is the upward force exerted by the liquid that opposes the weight of the block. The apparent weight of the block when submerged is the actual weight minus the buoyant force.

\[ W_{\text{liquid}} = W_{\text{air}} - B \]

4. **Set Up the Equation**:
We can rearrange the equation to find the buoyant force:

\[ B = W_{\text{air}} - W_{\text{liquid}} \]

5. **Substitute the Known Values**:
Substitute the known weights into the equation:

\[ B = 4 \, \text{N} - 3 \, \text{N} \]

6. **Calculate the Buoyant Force**:
Now perform the subtraction:

\[ B = 1 \, \text{N} \]

### Final Answer:
The buoyant force acting on the wooden block is **1 N**.

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