A spring has a spring constant of 130 N/m. You place a book of mass 1.2 kg on the spring and compress it 0.4 m. a. How much elastic potential energy is stored in the spring? (3 points) b. You release the book and it moves vertically upward. How fast is it moving when it passes the natural length of the spring? (4 points) . How high does the book go, compared with the natural length of the spring? (4 points)