A vertical spring stretches by 4.0cm when a block of mass 200g is hung from its lower end and comes to rest.
(i) Calculate the spring constant of the spring.
(ii) The block is pulled down slightly and released so that it performs small vertical oscillations. Determine the natural frequency of these oscillations. Take g=9.8ms−2.
(iii) If the block is now replaced by another block of mass 300g, calculate the new natural frequency of oscillation of the system.