In the vaulting events, gymnasts sprint down a 25 metres (82 ft) runway, jump onto a spring filled board or perform a roundoff, or handspring entry onto a springboard (run/ take-off segment), land momentarily, inverted on the hands on the vaulting horse, or vaulting table (pre flight segment), then propel themselves forward or backward, off of this platform to a two footed landing (post flight segment). Every gymnast starts at a different point on the vault runway depending on their height and strength. The post flight segment may include one or more multiple saltos or somersaults, and/or twisting movements. A round-off entry vault, called a Yurchenko, is the most common vault in elite level gymnastics. When performing a yurchenko, gymnasts "round-off" so hands are on the runway while the feet land on the springboard (beatboard). From the roundoff position the gymnast travels backwards and executes a backhandspring so that the hands land on the vaulting table. The gymnast then blocks off the vaulting platform into various twisting and/or somersaulting combinations. The post flight segment brings the gymnast to her feet.
How man feet do vaulters land on?
a two footed landing

The tide-predicting machine invented by Sir William Thomson in 1872 was of great utility to navigation in shallow waters. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location.
Who invented the first tide-predicting machine in 1872?
Sir William Thomson

The back of the cartridge bears a label with instructions on handling. Production and software revision codes were imprinted as stamps on the back label to correspond with the software version and producer. With the exception of The Legend of Zelda and Zelda II: The Adventure of Link, manufactured in gold-plastic carts, all licensed NTSC and PAL cartridges are a standard shade of gray plastic. Unlicensed carts were produced in black, robin egg blue, and gold, and are all slightly different shapes than standard NES cartridges. Nintendo also produced yellow-plastic carts for internal use at Nintendo Service Centers, although these "test carts" were never made available for purchase. All licensed US cartridges were made by Nintendo, Konami and Acclaim. For promotion of DuckTales: Remastered, Capcom sent 150 limited-edition gold NES cartridges with the original game, featuring the Remastered art as the sticker, to different gaming news agencies. The instruction label on the back included the opening lyric from the show's theme song, "Life is like a hurricane".
What color were cartridges produced by Nintendo for internal use?
yellow