Spring Force (Hooke's Law)

Practice: A 1.0 m-long spring is laid horizontally with one of its ends fixed. When you pull on it with 50 N, it stretches to 1.2 m. (a) What is the spring’s force constant (b) How much force is needed to compress it to 0.7 m?

Practice: You push a 3-kg mass against a spring and release it from rest. Its maximum acceleration is 10m/s² when pushed back 0.5m. What is the (a) spring constant and (b) restoring force at this point?