Multiple Choice
Which principle explains why certain insects can walk on water?
275
views
19. Fluid Mechanics
Buoyancy & Buoyant Force
Struggling with Physics?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which statement best explains the reason some insects can walk across the surface of a lake?
A
The insects are less dense than water, allowing them to float.
B
The insects have a special gas-filled sac that keeps them afloat.
C
The insects have hydrophobic legs that prevent them from sinking.
D
The insects are supported by the buoyant force of the water.
Verified step by step guidance1
Understand the concept of surface tension: Surface tension is a property of the liquid surface that allows it to resist an external force, due to the cohesive nature of its molecules.
Recognize the role of hydrophobic legs: Insects that walk on water often have legs that are hydrophobic, meaning they repel water. This property helps them to not break the surface tension of the water.
Consider the balance of forces: The weight of the insect is balanced by the surface tension force acting upwards, preventing the insect from sinking.
Differentiate from buoyancy: Unlike buoyancy, which involves the displacement of water, surface tension does not require the insect to be less dense than water.
Conclude with the correct explanation: The ability of insects to walk on water is primarily due to their hydrophobic legs interacting with the surface tension of the water, rather than buoyancy or density differences.
11:6mWatch next
Master Intro to Buoyancy & Buoyant Force with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Buoyancy & Buoyant Force practice set
Problem sets built by lead tutorsExpert video explanations