Suppose a spring with spring constant $2 \ \mathrm{N/m}$ is horizontal and has one end attached to a wall and the other end attached to a mass. You want to use the spring to weigh items. You put the spring into motion and find the frequency to be $0.9 \ \mathrm{Hz}$ (cycles per second). What is the mass? Assume there is no friction.

Mass = help (units)