Answer:
4.737 N/m
Explanation:
The period of a mass-spring system is calculated as
[tex]T=2\pi\sqrt{\frac{m}{k}}[/tex]Where m is the mass and k is the spring constant. Solving for k, we get
[tex]\begin{gathered} \frac{T}{2\pi}=\sqrt{\frac{m}{k}} \\ \\ (\frac{T}{2\pi})^2=\frac{m}{k} \\ \\ \frac{T^2}{4\pi^2}\cdot k=m \\ \\ T^2\cdot k=m(4\pi^2) \\ \\ k=\frac{m(4\pi^2)}{T^2} \end{gathered}[/tex]Then, replacing m = 750 g = 0.75 kg and T = 2.5s, we get:
[tex]k=\frac{0.75\text{ kg }\cdot4\cdot\pi^2}{(2.5\text{ s\rparen}^2}=4.737\text{ N/m}[/tex]Therefore, the spring constant must be 4.737 N/m