Situation 1: When a 4.00-kg object is hung vertically on a certain light spring that obeys Hooke's law, the spring stretches 2.50 cm. If the 4.00-kg object is removed, 15. What is the value of the spring constant k? 16. How far will the spring stretch if a 1.50-kg block is hung on it and 17. How much work must an external agent do to stretch the same spring 4.00 cm from its unstretched position?

Situation 1: When a 4.00-kg object is hung vertically on a certain light spring that obeys Hooke's law, the spring stretches 2.50 cm. If the 4.00-kg object is removed, 15. What is the value of the spring constant k? 16. How far will the spring stretch if a 1.50-kg block is hung on it and 17. How much work must an external agent do to stretch the same spring 4.00 cm from its unstretched position?