A 2000-kg elevator with broken cables in a test rig is falling at 4.00 m/s when it contacts
a cushioning spring at the bottom of the shaft. The spring is intended to stop the elevator,
compressing 2.00 m as it does so. During the motion a safety clamp applies a constant
17,000-N friction force to the elevator. What is the necessary force constant k for the
spring? (1.06 x 104 N/m)