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A propeller is a type of fan which transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and air or water is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's principle and Newton's third law. Aircraft propellers convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch...

The 19th century (1801–1900) was a period in history marked by the collapse of the Spanish, Portuguese, Chinese, Holy Roman and Mughal empires. This paved the way for the growing influence of the British Empire, the German Empire and the United States, spurring military conflicts but also advances in science and exploration...

The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. Although originally designed for dictation, improvements in fidelity led the Compact Cassette to supplant reel-to-reel tape recording in most non-professional applications. Its uses ranged from portable audio to home recording to data storage for early microcomputers...

Red Bull is an adaptation of the Thai energy drink Krating Daeng, which means 'Red Bull'. The company was founded by Thai national Chaleo Yoovidhya and Austrian national Dietrich Mateschitz. Together with his son, Chaleo owns a controlling 51 percent interest in the company; however, Mateschitz is responsible for the company's operations through the Austrian company Red Bull GmbH...

Jeans are trousers made from denim. Jeans, originally designed for work, became popular among teenagers starting in the 1950s. Historic brands include Levi's, Lee and Wrangler. Jeans come in various types, for example, skinny jeans, boot cut, or flare. Jeans are now a very popular form of casual dress around the world, and have been so for decades. They come in many styles and colors; however, "blue jeans" are particularly identified with American culture, especially the American Old West...

A pet is an animal kept for companionship and enjoyment or a household animal, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful characteristics, for their attractive appearance, or for their song...