When we rub our hands Which of the following is True ?

Options

A. kinetic energy changes into potential energy
B. mechanical energy changes into heat energy.
C. potential energy changes into kinetic energy.
D. heat energy changes into mechanical energy.

Answer

To solve the question about what happens when we rub our hands, we can analyze the options provided and understand the energy transformations involved.

### Step-by-Step Solution:

1. **Understand the Action**: When we rub our hands together, we are performing a mechanical action. This involves moving our hands against each other.

**Hint**: Think about what kind of movement is involved when you rub your hands.

2. **Identify the Types of Energy**: In this process, we have different forms of energy at play:
- **Kinetic Energy**: This is the energy of motion. When we rub our hands, they are moving, which means kinetic energy is present.
- **Potential Energy**: This energy is stored due to the position of the hands, but it is not the main focus here.
- **Heat Energy**: This is the energy that is generated due to friction when the surfaces of our hands rub against each other.

**Hint**: Consider the energy involved in the motion of your hands and the heat produced.

3. **Friction and Heat Generation**: As we rub our hands, friction occurs between the surfaces of our skin. This friction converts some of the mechanical energy (from the motion of rubbing) into heat energy.

**Hint**: Think about why your hands feel warm after rubbing them together.

4. **Evaluate the Options**: Now, let's look at the options provided:
- **Option 1**: Kinetic energy changes into potential energy - This is incorrect because there is no significant conversion happening in this scenario.
- **Option 2**: Mechanical energy changes into heat energy - This is correct as explained above.
- **Option 3**: Potential energy changes into kinetic energy - This is also incorrect in this context.
- **Option 4**: Heat energy changes into mechanical energy - This is incorrect because we are not converting heat back into mechanical energy in this action.

5. **Conclusion**: Based on the analysis, the correct answer is that when we rub our hands, the mechanical energy changes into heat energy.

**Final Answer**: The correct option is **Option 2: Mechanical energy changes into heat energy**.