In the following questions a statement of assertion (A) is followed by a statement of reason ( R).
A: Unifrom circular motion is accelerated motion stil speed remains unchanged .
R: Instantaneous velocity is always normal to instantaneous acceleration in uniform circular motion.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion then mark (1) .
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark (2)
C. If Assertion is true statement but Reason is false then mark (3).
D. If both Assertion and Reason are false statements then mark (4) .

Answer

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Understand the Assertion (A)
The assertion states that "Uniform circular motion is accelerated motion still speed remains unchanged."

- **Explanation**: In uniform circular motion, an object moves in a circular path at a constant speed. Although the speed (the magnitude of velocity) remains constant, the direction of the velocity changes continuously. Since acceleration is defined as the change in velocity over time, and velocity is a vector quantity (having both magnitude and direction), the change in direction implies that there is an acceleration present, even though the speed does not change.

### Step 2: Understand the Reason (R)
The reason states that "Instantaneous velocity is always normal to instantaneous acceleration in uniform circular motion."

- **Explanation**: In uniform circular motion, the instantaneous velocity vector is tangent to the circular path at any point, while the instantaneous acceleration vector points towards the center of the circle (centripetal acceleration). This means that the two vectors are perpendicular (normal) to each other. This perpendicular relationship indicates that the acceleration does not change the speed of the object, only its direction.

### Step 3: Analyze the Relationship Between A and R
- The assertion (A) is true because uniform circular motion is indeed an accelerated motion with constant speed.
- The reason (R) is also true because the instantaneous velocity is indeed normal to the instantaneous acceleration in uniform circular motion.

### Step 4: Conclusion
Since both the assertion and reason are true, and the reason correctly explains the assertion, the answer to the question is that both statements are true, and the reason supports the assertion.

### Final Answer
Both the assertion (A) and the reason (R) are true, and the reason explains the assertion.

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