A block of weight `9.8N` is placed on a table. The table surface exerts an upward force of `10N` on the block. Assume `g=9.8m//s^(2)`.

Options

A. The block exerts a force of `10N` on the table
B. The block exerts a force of `19.8N` on the table
C. The block exerts a force of `9.8N` on the table
D. The block has an upward acceleration.

Explanation

To solve the problem, we need to analyze the forces acting on the block placed on the table.

### Step-by-Step Solution:

1. **Identify the Weight of the Block**:
The weight of the block is given as \( W = 9.8 \, \text{N} \). This weight acts downwards due to gravity.

2. **Identify the Upward Force from the Table**:
The table exerts an upward force (normal force) on the block, which is given as \( F_{\text{up}} = 10 \, \text{N} \).

3. **Apply Newton's Third Law of Motion**:
According to Newton's Third Law, for every action, there is an equal and opposite reaction. Therefore, the block exerts a force on the table equal to the upward force it experiences.
- The block exerts a downward force of \( 10 \, \text{N} \) on the table.

4. **Determine the Net Force on the Block**:
To find the net force acting on the block, we can subtract the weight of the block from the upward force:
\[ F_{\text{net}} = F_{\text{up}} - W = 10 \, \text{N} - 9.8 \, \text{N} = 0.2 \, \text{N} \]
Since the net force is positive, it indicates that the block is accelerating upwards.

5. **Conclusion**:
- The block exerts a force of \( 10 \, \text{N} \) on the table.
- The block experiences an upward acceleration because the upward force exceeds its weight.

### Summary of Options:
- **Option 1**: The block exerts a force of \( 10 \, \text{N} \) on the table. (Correct)
- **Option 2**: The block exerts a force of \( 19.8 \, \text{N} \) on the table. (Incorrect)
- **Option 3**: The block exerts a force of \( 9.8 \, \text{N} \) on the table. (Incorrect)
- **Option 4**: The block has an upward acceleration. (Correct)

### Final Answer:
The correct options are 1 and 4.

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