On february 15, 2013, a superbolide meteor (brighter than the sun) entered earth’s atmosphere over chelyabinsk, russia, and exploded at an altitude of 23.5 km. eyewitnesses could feel the intense heat from the fireball, and the blast wave from the explosion blew out windows in buildings. the blast wave took approximately 2 minutes 30 seconds to reach ground level. (a) what was the average velocity of the blast wave? (b) compare this with the speed of sound, which is 343 m/s at sea level.

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.