In an amusement park ride, a passenger capsule is attached to two stretched elastic cords. The cords behave like ideal springs.

Before the capsule is released, the extension of each of the two elastic cords is 10 m10\text{ m}10 m.
The spring constant of each elastic cord is 490 N/m490\text{ N/m}490 N/m.
The total mass of the capsule and passengers is 200 kg200\text{ kg}200 kg.
The gravitational field strength is g=9.8 N/kgg = 9.8\text{ N/kg}g=9.8 N/kg.
State the energy store that increases as the elastic cords are stretched.
Calculate the maximum height reached by the capsule, assuming no energy is lost to the surroundings.
In reality, the actual maximum height reached by the capsule is lower than this calculated value. Explain why.