1. The problem statement, all variables and given/known data As a 15000 kg jet plane lands on an aircraft carrier, its tail hook snags a cable to slow it down. The cable is attached to a spring with spring constant 60000 N/m. If the spring stretches 30 m to stop the plane, what was the plane's landing speed? 2. Relevant equations m=15000 kg k = 60000 N/m d = 30 m 3. The attempt at a solution I assume Hook's Law is involved here somewhere, F = kx = 60000*30 = 1800000. Beyond this, I'm lost about where to go. Can anyone help? Thanks.