Explain the following:
Cooking utensils are often blackened at the bottom but polished at the top and sides.

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Cooking Utensils**: Cooking utensils are designed to facilitate the cooking process. The bottom of these utensils is often blackened, while the sides and top are polished.

2. **Reason for Blackening the Bottom**: The bottom of the cooking utensil is blackened to increase its ability to absorb heat. Black surfaces are known to be better absorbers of heat due to their higher emissivity. This means that when the utensil is placed on a heat source (like a stove), it can absorb heat more efficiently, leading to faster cooking of the food inside.

3. **Reason for Polishing the Sides and Top**: The sides and top of the cooking utensil are polished to reduce heat loss through radiation. Polished surfaces have lower emissivity, which means they emit less heat. By polishing these areas, the utensil retains more heat, allowing the food to cook evenly without losing too much heat to the surrounding environment.

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