In which of the following applications is nylon typically used?

Nylon is commonly used in applications that require materials with excellent mechanical properties, such as high tensile strength, good abrasion resistance, and the ability to operate under wear and friction. Bearings, in particular, benefit from these properties as they must endure significant stresses during operation. The self-lubricating nature of nylon also reduces wear and prolongs the lifespan of bearings, making it a suitable choice for various mechanical applications.

In contrast, window frames are typically made of materials like PVC or aluminum due to their structural integrity and weather resistance. CD cases are often manufactured from polycarbonate or polystyrene, which offer clarity and impact resistance. Plastic bottles are generally made from PET, a material chosen for its flexibility, strength, and recyclability. Thus, nylon’s unique characteristics make it an ideal material for bearings among the options provided.