Joule's experiment converts

Options

A. work into heat
B. work into electricity
C. heat into work
D. electricity into work

Answer

### Step-by-Step Solution:

1. **Understanding Joule's Experiment**: Joule's experiment was designed to demonstrate the relationship between work and heat. In the experiment, a mass is attached to a pulley system that is used to lift and lower the mass.

2. **Setup Description**: The setup consists of a container filled with water, which is insulated to prevent heat loss. A mass is connected to a rope that goes over a pulley. When the mass is lifted, work is done on the system.

3. **Work Done**: When the mass is pulled down, it loses potential energy. This loss in potential energy is equal to the work done on the system. The work done can be calculated using the formula:
\[ \text{Work} = \text{Force} \times \text{Distance} \]
Here, the force is the weight of the mass and the distance is how far it is lifted.

4. **Conversion of Energy**: As the mass is lifted and lowered, the work done is converted into thermal energy (heat) in the water. This is due to friction and the movement of the mass, which causes the water's temperature to rise.

5. **Heat Calculation**: The heat generated can be calculated using the formula:
\[ Q = m \cdot c \cdot \Delta T \]
where \( Q \) is the heat produced, \( m \) is the mass of the water, \( c \) is the specific heat capacity of water, and \( \Delta T \) is the change in temperature.

6. **Conclusion**: Therefore, Joule's experiment demonstrates that work can be converted into heat. The correct answer to the question is:
- **Option 1: Work into Heat**.