How do you find the elastic constant on a force extension graph?

The plum pudding model of the atom states that ?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.