A 5.0g 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 20 m above the marble's position on the compressed spring. (a) What is the change `DeltaU_(g)` in the gravitational potential energy of the marble-Earth system during the 20 m ascent ? (b) What is the change `DeltaU_(s)` in the elastic potential energy of the spring during its launch of the marble ? (c) What is the spring constant of the spring ?

Answer

(a) 0.98 J ; (b) - 0.98 J ; (c) 3.1 N/cm