A hiker inspects a tree frog sitting on a small stick in his hand. Suddenly startled, the hiker drops the stick from rest at a height of 1.80 m above the ground and, at the same instant, the frog leaps vertically upward, pushing the stick down so that it hits the ground 0.420 s later. Find the height of the frog at the instant the stick hits the ground if the frog and the stick have masses of 7.45 g and 4.30 g, respectively. (Hint: Find the center-of-mass height at t = 0.420 s for the frog-stick system and then use the definition of center of mass to solve for the frog's height. Enter your answer in m.)