John measures the angle of elevation to the top of a cliff to be 23 degrees. He walks 720 metres horizontally towards the cliff and finds the angle of elevation has doubled. What is the height of the cliff to the nearest metre ?

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =