The principle of inertia was first stated by

Options

A. Newton
B. Galileo
C. Kepler
D. Bruno

Answer

To solve the question regarding who first stated the principle of inertia, we can follow these steps:

### Step 1: Understand the Principle of Inertia
The principle of inertia states that if no net force acts on a body, the body will maintain its state of rest or uniform motion in a straight line. This concept is foundational in physics and relates to the behavior of objects when forces are applied or absent.

### Step 2: Identify the Contributors
The principle of inertia is closely associated with two key figures in physics: Galileo Galilei and Sir Isaac Newton. While both contributed to the understanding of motion, their contributions were made at different times.

### Step 3: Acknowledge Galileo's Contribution
Galileo Galilei was the first to articulate the principle of inertia. He proposed that an object in motion stays in motion unless acted upon by an external force. This was a significant departure from the Aristotelian view of motion.

### Step 4: Recognize Newton's Role
Sir Isaac Newton later formalized this principle in his first law of motion, which is often referred to as the law of inertia. However, Newton's formulation came after Galileo's initial statement of the principle.

### Step 5: Conclusion
Based on the historical context, the principle of inertia was first stated by Galileo Galilei. Therefore, the correct answer to the question is Galileo Galilei.

### Final Answer
The principle of inertia was first stated by Galileo Galilei.

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