Although the altitude may vary considerably, hailstonessometimes originate around 500m (about 1500ft) above theground. a) Neglecting air drag, how fast will these hailstones bemoving when they reach the ground, assuming that they started fromrest? Express your answer in m/s and in mph. Although the altitude may vary considerably, hailstonessometimes originate around 500m (about 1500ft) above theground. a) Neglecting air drag, how fast will these hailstones bemoving when they reach the ground, assuming that they started fromrest? Express your answer in m/s and in mph.
Explanation / Answer
Potential energy is converted to kinetic energy, so: -- mgh = 1/2mv^2 -- gh = 1/2v^2 ----> mass cancels -- v = (2gh) v = 99.0 m/s -- In mph: -- (99 meters/sec)(3.28 feet/1 meter)(60 seconds/1 minute)(60minutes/1 hour)(1 mile/5280 feet) = 221 mph -- -- Hope this helps.