posted by Sarah .
Suppose I throw a ball straight up at an initial speed of 10 m/s. Suppose I'm 2 meters tall (about 6 feet) and the ball leaves my hand at 2 meters from the ground. How fast is it going at its highest point? How fast is it going on its way back down at 2 meters above the ground. Justify reasoning.
Give me a break. At the highest point its vertical velocity is zero. When it comes back down, it has the same velocity as it started (conservation of energy), but in a downward direction.