Question

The thickness of the ice layer on the surface of a lake is 20 m. A hole is made in the ice layer. What is the minimum length of the rope required to take a bucket full of water?

• A. 2 m
• B. 18 m
• C. 5 m
• D. 9 m

Hint:

For problems involving submerged objects, always consider the vertical distance from the surface to the bottom.

Answer 1

The Correct Option is D

Step 1: Understanding the situation.
The ice thickness is given as 20 m, which means that the depth of water under the ice is 20 m. To lift a bucket full of water, the rope needs to cover the distance from the top of the ice to the bottom of the lake. Step 2: Minimum rope length calculation.
The minimum length of rope needed is the sum of the thickness of the ice and the distance to reach the water under the ice, which is 20 m. Hence, the rope required is the same length as the ice thickness: \( 9 m \). Step 3: Conclusion.
The correct answer is (4) 9 m.