What is the spring constant in N/m?

Question

A 2.0-kg mass is connected to a spring on a horizontal, frictionless surface. The mass is undergoing simple harmonic motion with an amplitude of 50 cm and a period of 2 seconds. What is the spring constant in N/m? 

Answer 1

For a spring in harmonic motion, period = 2π√m/k, where m is mass and k is the spring constant. So m/(period/2π)²=k. k = 19.74 N/m