We are able to walk because of ____________.

Options

A. Speed
B. Motion
C. Friction
D. None of these

Answer

To solve the question "We are able to walk because of ____________," we can follow these steps:

### Step 1: Understand the Question
The question is asking for the reason behind our ability to walk. We need to identify the physical principle or force that enables walking.

**Hint:** Think about the forces that act when we move our feet on the ground.

### Step 2: Analyze the Options
The options provided are:
1. Speed
2. Motion
3. Friction
4. None of these

**Hint:** Consider each option and how it relates to the process of walking.

### Step 3: Apply Newton's Third Law
According to Newton's Third Law of Motion, for every action, there is an equal and opposite reaction. When we push our feet against the ground, we exert a force downward.

**Hint:** Remember that the ground reacts to our action by pushing back.

### Step 4: Identify the Role of Friction
When we walk, our foot pushes backward against the ground. The ground pushes forward against our foot due to friction. This frictional force is what allows us to move forward.

**Hint:** Think about what happens when you try to walk on a slippery surface versus a rough surface.

### Step 5: Conclusion
Based on the analysis, we conclude that we are able to walk because of friction. Therefore, the correct answer is:

**Answer:** Friction

### Final Answer
We are able to walk because of **friction**.

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