A flowerpot is knocked odd a balcony from a height (d) above the sidewalk. It falls toward an unsuspecting man of height (h) who is standing below. Assume the man requires a time interval of (?t) to respond to the warning. How close to the sidewalk can the flowerpot fall before it is too late for a warning shouted from the balcony to reach the man in time? Use the symbol (v) for the speed of sound.