Factors 1
Water bottle
Strong, light, waterproof.
Chair
Durable enough to hold weight, be stable, and comfortable.
Backpack Strap
Fabric, nylon (plastic).
Bicycle frame
Metal: Aluminum, steel, or carbon fiber.
Spoon
Needs to handle heat and be safe to use with food.
Ball
Depends on the type of ball! but most of the time, must bounce and be strong but not hard.
Water bottle
Plastic, metal.
Phone Case
Rubber, silicone, or hard plastic.
Window
Needs to be transparent, strong, and weatherproof.
Lamp
Should resist heat and look good.
Chair
Wood, metal, or plastic.
Spoon
Metal or wood. (Sometimes plastic for lightness & discardability)
Phone Case
Must protect the phone, be light, and not slip easily.
Bicycle Frame
Must be strong, be able to take impact/jumps, but light.
Window
Glass or strong clear plastic.
Ball
Rubber or synthetic leather.
Backpack strap
Has to be strong but soft and flexible.
Umbrella
Should block water, resist wind, and fold easily.
Lamp
Metal, glass, or plastic.
Umbrella
Fabric, metal, and plastic handle or cover.