1. A block of mass 1 kg, on a frictionless surface, is attached to two springs as shown in the figure. One spring has a force constant of 50 N/m while the other 150 N/m. When the block is at the centre, both springs are relaxed. (a) If the block is displaced by a small distance r, what is the net force on it? [2 pts] (b) The block is displaced by 10 em and released. Briefly describe the resulting motion. [1 pt] (c) Draw three plots of energy vs. time: (i) kinetic energy and (ii) potential energy in the 50 N/m spring, and (iii) potential energy in the 150 N/m spring. Show precise values for any maxima, minima or time periods. [4 pts]