Question

Before 1962, few astronomers believed that the universe contained celestial bodies that were hot enough to emit X-rays-about 10,000 times hotter than the surface of the Sun. Because the atmosphere absorbs the X-rays produced by such sources, they can only be detected beyond Earth's atmosphere, 200 km or more above Earth's surface. Before satellites were available in the 1970s, scientists searched for X-ray sources by launching rockets (the first in 1962 from White Sands Missile Range in New Mexico) that contained detectors that could sample the skies for the short time interval that the rocket remained above the atmosphere-less than 10 min. Such a Terrier-Sandhawk rocket was flown on May 11, 1970 from the Kauai Test Range in Hawaii. Modern satellites can collect data continuously. Satellite observations and analysis have now identified several types of celestial bodies that emit X-rays, including X-ray pulsars in the constellations of Cygnus and Hercules, supernovae remnants, and quasars.

During fuel burn, the vertically launched Terrier-Sandhawk rocket had an acceleration of 300 m/s2 (about 30 times free-fall acceleration called 30 g). The fuel burned for 9.0 s . Find the time interval after fuel burned that the Terrier-Sandhawk rocket reached its maximum height. Use g=9.8m/s2.

Answer 1