Use the following to answer questions 6 and 7. The displacement of a spring versus the position of the wave along the spring is shown: 6 2 () cm A 2 D - 2 AAA a 6. The waves have a speed of 7.1 cm/s. What is the period of the waves? a. .25 s b. .49 s c. .85 s d. 1.3 s 7. The above waves use to have an amplitude of 11 cm and an energy content of 198 J. Using the information in the above graph, what is the energy content of the waves shown in the graph? a. 33.7 J b. 26.2 J c. 12.9 J d. 45.5 J