Wanting to invite Juliet to his party, Romeo is throwing pebbles at her window with a launch angle of 73° from the horizontal. He is standing at the edge of the rose garden 7.0 m below her window and 16.9 m from the base of the wall. What is the initial speed of the pebbles? (Assume the pebble travels a vertical distance of 7.0 m and strikes the window before it can reach its maximum height.)