Chapter 10.4, Problem 47ES

To prepare astronauts for the experience of zero gravity (technically. microgravity) in space, the National Aeronautics and Space Administration (NASA) uses a specially designed jet. A pilot accelerates the jet upward to an altitude of approximately 9000 m and then reduces power. At that time, the plane continues upward, noses over, and begins to descend until the pilot increases power. The maneuver is then repeated. The figure at the right shows one such maneuver.

The altitude $A\left(t\right)$, in meters, of the jet t seconds after power has been reduced can be approximated by $A\left(t\right)=-4.9t^2+90+900$. If the pilot increases power when the plane descends to 9000 m. thereby ending microgravity, for how long do the astronauts experience microgravity during one of these maneuvers? Round to the nearest tenth of a second.