A force acting normal to a surface is called________

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term used to describe a force that acts perpendicular (normal) to a surface.

2. **Identifying the Force**: When an object is placed on a surface, the weight of the object (due to gravity) acts downward. This weight is represented as \( mg \), where \( m \) is the mass of the object and \( g \) is the acceleration due to gravity.

3. **Normal Force**: In response to the weight of the object, the surface exerts an upward force on the object. This force acts perpendicular to the surface and is known as the normal force.

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