7. Four identical masses are connected by five identical springs between two rigid walls as illustrated in the figure and move without friction on a horizontal surface. How many normal modes of vibration in the transverse direction does the system have? Sketch these normal modes bearing in mind that the transverse positions of masses pass through sinusodial curves. K K K K m m

7. Four identical masses are connected by five identical springs between two rigid walls as illustrated in the figure and move without friction on a horizontal surface. How many normal modes of vibration in the transverse direction does the system have? Sketch these normal modes bearing in mind that the transverse positions of masses pass through sinusodial curves. K K K K m m