Assertion: A child in a garden swing periodically presses his feet against the ground to maintain the oscillations.
Reason: All free oscillations eventually die out because of the ever present damping force.

Options

A. If both assertion and reson are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To analyze the given assertion and reason, let's break down the problem step by step:

### Step 1: Understand the Assertion
The assertion states that "A child in a garden swing periodically presses his feet against the ground to maintain the oscillations." This implies that the child is applying a force to keep the swing moving back and forth.

**Hint for Step 1:** Consider what actions are taken to maintain motion in oscillatory systems.

### Step 2: Identify the Type of Oscillation
The action of the child pressing his feet against the ground is an example of forced oscillation. In forced oscillation, an external force is applied to maintain the motion of the system. The frequency of the oscillation is determined by the frequency of the external force applied.

**Hint for Step 2:** Think about how external forces influence the motion of oscillating systems.

### Step 3: Understand the Reason
The reason states that "All free oscillations eventually die out because of the ever-present damping force." Free oscillations occur without any external force, and they can be damped due to factors like friction or air resistance, which causes the amplitude of oscillation to decrease over time.

**Hint for Step 3:** Recall the difference between free and forced oscillations and how damping affects them.

### Step 4: Evaluate the Truth of Both Statements
Both the assertion and reason are true:
- The assertion is true because the child indeed needs to apply force to keep swinging.
- The reason is also true as free oscillations do eventually die out due to damping forces.

**Hint for Step 4:** Consider whether both statements are accurate and if one explains the other.

### Step 5: Determine the Relationship Between Assertion and Reason
The reason does not directly explain the assertion. While both statements are true, the reason discusses free oscillations, whereas the assertion is about forced oscillations. Therefore, the reason does not provide a correct explanation for the assertion.

**Hint for Step 5:** Analyze if the reason logically supports or explains the assertion.

### Conclusion
After evaluating both the assertion and the reason, we conclude that:
- Both the assertion and reason are true.
- However, the reason is not a correct explanation of the assertion.

Thus, the correct answer would be that both statements are true, but the reason does not explain the assertion.

### Final Answer
Both the assertion and reason are true, but the reason is not a correct explanation of the assertion.