Why does a block of plastic released under water come up to the surface of water?

Explanation

To understand why a block of plastic released underwater comes up to the surface of the water, we can break down the explanation into several key steps:

### Step-by-Step Solution:

1. **Understanding Density**:
- The first thing to note is that the density of the plastic block is less than the density of water. This is a crucial factor in determining whether an object will float or sink.

2. **Buoyant Force**:
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