The amount of force to be applied on the spanner at a length of 0.25 m from the bolt is 400 N. Find the torque to open a bolt.

Answer

To find the torque required to open the bolt using a spanner, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula for Torque**:
The torque (τ) is calculated using the formula:
\[ \tau = \text{Force} \times \text{Distance} \]
where:
- τ is the torque,
- Force is the applied force,
- Distance is the length from the pivot point (in this case, the bolt) to the point where the force is applied.

2. **Identify the Given Values**:
From the question, we have:
- Force (F) = 400 N
- Distance (d) = 0.25 m

3. **Substitute the Values into the Formula**:
Now, we can substitute the given values into the torque formula:
\[ \tau = 400 \, \text{N} \times 0.25 \, \text{m} \]

4. **Calculate the Torque**:
Performing the multiplication:
\[ \tau = 400 \times 0.25 = 100 \, \text{N m} \]

5. **State the Final Answer**:
Therefore, the torque required to open the bolt is:
\[ \tau = 100 \, \text{N m} \]