Q1.7 (14 points) (Vertical motion under constant acceleration) A tourist brings a toy-gun to visit one of the tallest dams in the world. The dam is the Jinping-I Dam in Sichuan with a height of 305 m from water level. For simplicity we assume the dam is vertical. The tourist shoots an object vertically upwards at 30 m/s from the top of the dam. How high does the object rise? How long is it in air? What is the velocity when the object hits the water