1. The problem statement, all variables and given/known data A 4.8 g marble is fired vertically upward using a spring gun. The spring must be compressed 8.0 cm if the marble is to just reach a target 27 m above the marble's position on the compressed spring. (a) What is the change in the gravitational potential energy of the marble-Earth system during the 27 m ascent? (a) ? J (b) What is the change in the elastic potential energy of the spring during its launch of the marble? (b) ? J (c) What is the spring constant of the spring? (c) ? N/m 2. The attempt at a solution (a) 27 - .080 = 26.92 (26.92)(9.8)(.0048) = (1/2)(.0048)v^2 v = 22.97 <<<< Isn't this the answer? But it's wrong. (b) (1/2)(the answer to c: ?)(.080)^2 (c) (1/2)(.0048)(the answer to a: 22.97?)^2 + (.0048)(9.8)(.080) = (1/2)(k)(.080)^2 k = ?