Determine the parallax (in arcseconds) of Mercury at superior conjunction, and sketch the useful geometry. Recall that Mercury is about 0.387 AU from the Sun.

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.