A spring has force constant 8.3 Nm^-1. A 0.075kg mass is hung on the end of the spring. It is set oscillating in simple harmonic motion by extending the mass downwards 4 cm below the central postion and releasing it. The period is 0.6 and the angular frequency, w, is 10.47 rad/s and the max. velocity is 0.42 m/s. Draw a reference circle to show the mass at the top and also at 1 cm above the bottom position, travelling downwards, then calculate the time taken to go between these two positions.