## Step 1: Analyze the Pulse Movement At **t = s**, the pulse is moving toward the end (right side of the, where the rod is shown). At **t = 1 s**, the pulse has moved 80 cm to the right (since speed = 80 cm/s × 1 s). Each square is 10 cm, so the pulse moves 8 squares to the right. **Observation:** The pulse shape at t = 1 s is not inverted; it retains its original orientation after reaching the end. The entire pulse shifts right, and its peak remains upwards. **Explanation:** - If the end was **fixed**, the pulse would invert (flip upside down) after reflection. - If the end was **free**, the pulse would reflect without inversion. --- ## Step 2: Identify the Nature of the End Since the pulse at t = 1 s is not inverted (it looks the same as at t = s but shifted to the right), this means the pulse reflected without inversion. **Explanation:** **No inversion of the pulse** indicates a **free end**. If it were a fixed end, the pulse would be inverted after reflection. --- ## **Final Answer** **The end of the spring is a free end.** The pulse reflected without inversion, which only happens at a free end. --- ### Handwritten Explanation and Diagram Guide To provide a handwritten answer, draw: - The initial pulse at t = s approaching the end. - The pulse at t = 1 s, reflected but not inverted, matching the diagram. - Annotate: “No inversion ⇒ Free end” --- If you want a sample handwriting, let me know!