High performance aircraft pilots and astronauts experience "g" or gravity force when they perform or are involved in some maneuvers. Under certain conditions like a tight turn, a pull up, or when experiencing a space shuttle take-off, the pilot or astronauts will feel multiple "g" forces. In effect, a 180-pound pilot or astronaut experiencing 3 g's will weigh 540 pounds. High "g" loads upon the human body can cause disorientation, blackout and could have a fatal result. To train as a high performance pilot or astronaut, a device called a centrifuge has been developed to simulate "g" loads on a human. A centrifuge travels an object in a circular path. It operates similar to a merry-go-round at an amusement park except it can be programmed to go around much faster. There is a formula that can be used to calculate the g's a person feels when training on a centrifuge. g's = 4 ´ p 2 ´ DT / 32 ´ TP2 DT = Distance from the Turning Point TP = Turning Period The turning period is the time it will take a rider to make one complete turn. A pilot/astronaut-training centrifuge has a diameter of 30 feet.  It will spin the person 15 feet from the centrifuge's center point. It will take the astronaut 4 seconds to make one complete turn. The circumference or distance around is 30 p or approximately 94 feet. How many "g's", will the astronaut feel? What will be the astronaut's approximate comparable speed in miles per hour? Given: p = 3.14 g = 4 ´ 3.142 ´ (15 feet) / 32 ´ 42 g = 592 / 512 = 1.16 So the astronaut will feel 1.2 g's And the astronaut's speed will be: Speed in miles per hour = (94 ft / 4 sec) ´ (1 mile / 5,280 ft) ´ (3,600 sec /1 hour) Speed = 338,400 mile / 21,120 hours or 16 miles per hour Using the same centrifuge information from the above example (30 feet diameter), how long a turning period - in seconds - will the centrifuge take so the pilot/astronaut feels 4 g's, and how fast will that be in miles per hour? Estimate the answer: 1.8 seconds and 35.6 miles per hour 3.4 seconds and 18.9 miles per hour 2.1 seconds and 30.5 miles per hour