A pellet gun is fired straight downward from the edge of a cliff that is above the ground. The pellet strikes the ground with a speed of . Barrett .50 Caliber is fired with the speed of 2700 feet per second. How far above ground does the Barrett .50 Caliber need to be to strike the ground at the same time as the pellet gun? A dynamite blast at a quarry launches a chunk of rock straight upward, and later it is rising at a speed of . Assuming air resistance has no effect on the rock, how long does it take for the rock to reach the ground?