waterproof
Definition
Waterproof is a property of a material that prevents water from passing through it. This is achieved by creating a barrier between the water and the material. There are many different ways to make a material waterproof, including:
- Using a coating of rubber or plastic.
- Treating the material with a chemical that makes it water-resistant.
- Weaving the material in a way that creates tiny gaps that are too small for water molecules to pass through.
The degree of water resistance of a material is measured by its water-column rating. This is the amount of water pressure that the material can withstand before it starts to leak. For example, a raincoat with a water-column rating of 500 millimetres will not leak if it is exposed to raindrops that are falling at a pressure of 500 millimetres of water.
How can the word be used?
The container is waterproof.
Different forms of the word
Adjective: not allowing water to pass through.
Noun: a material that is waterproof.
Etymology
The word "waterproof" comes from the combination of the words "water" and "proof".
The word "water" comes from the Old English word "wæter", which means "water".
The word "proof" comes from the Old English word "prūf", which means "test" or "trial".
The first recorded use of the word "waterproof" was in the 17th century.
Question
Why is waterproof clothing important to a mountaineer?
AQA Science Exam Question and Answer
Question:
Explain the concept of waterproof materials and the scientific principles behind their effectiveness. Discuss how surface tension, hydrophobicity, and molecular structure contribute to the waterproofing of various objects.
Answer:
Waterproof materials are substances or coatings that prevent the penetration of water, making them impermeable to moisture. The effectiveness of waterproofing relies on several scientific principles, including surface tension, hydrophobicity, and molecular structure.
Surface tension is a key factor in waterproofing. Water molecules exhibit a cohesive force that creates a "skin" on the water's surface. Waterproof materials take advantage of this property by repelling water, preventing it from breaking through the surface tension barrier.
Hydrophobicity, or the "fear of water," plays a crucial role in waterproofing. Materials with hydrophobic properties have structures that repel water molecules, causing them to bead up and roll off the surface rather than being absorbed.
The molecular arrangement of waterproof materials is designed to minimize contact with water. This can involve creating a physical barrier through densely packed molecules or incorporating structures that hinder water infiltration.
Waterproof materials find application in a variety of objects, from clothing and shoes to electronic devices and building materials. They protect against water damage, corrosion, and mould growth by preventing water from seeping into the material.