Name two contact forces.

Explanation

**Step-by-Step Solution:**

1. **Understanding Contact Forces**: Contact forces are forces that occur when two objects are in physical contact with each other. They arise from the interaction between the surfaces of the objects.

2. **Identifying Examples**: We need to identify two specific examples of contact forces.

3. **First Example - Normal Force**:
- When an object is placed on a surface, it exerts a downward force due to its weight (mg).
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