When a pilot is subjected to a large acceleration for example, when performing aerobatic stunts they are said to have "pulled 3g" in that maneuver. Sometimes people use the term "g-force" to describe being pressed into your seat, but in this class we must be clear. There is no g-force. Just as in the previous example with the elevator, a person's apparent weight changes while accelerating, and we can measure that acceleration as a multiple of g = 9.8 m/s. When experiencing high acceleration, people can experience a loss of color vision or peripheral vision ("grey out"), a complete loss of vision ("black out"), or a loss of consciousness, due to lack of blood pressure in the brain. The onset of these conditions depends on both the acceleration and the length of time that the pilot is experiencing the acceleration. A typical person (unlike trained fighter pilots) will generally be safe with an acceleration of 4g for under 5 seconds. (a) Consider a plane flying at a constant speed of 300 km/hr in a horizontal circle whose radius is 200 m. What is the magnitude of the centripetal acceleration experienced by the pilot? Is it under 4g? (b) Now consider a 50 kg stunt pilot going from a vertical dive downwards into a vertical climb upwards by following, at a constant speed of 300 km/hr, the arc of a circle whose radius is 200 m. At the bottom of the circle, what is the net force (magnitude and direction) acting on the pilot? (c) At the bottom of the circle, what is the force exerted by the airplane seat on the pilot?