Question

A mass of 1 kg is attached to two identical springs each with stiffness k =20 kN/m as shown in the figure. Under frictionless condition, the natural frequency of the system Hz is close to

• A. 32
• B. 23
• C. 16
• D. 11

Answer 1

The correct option is A 32

Since springs are in parallel

$K_{\text{equivalent}}=k+k=2k$

$\therefore \text{Frequency}=\frac{1}{2\pi }\sqrt{\frac{2k}{m}}$

$\frac{1}{2\pi }\sqrt{\frac{2\times 20\times {10}^3}{1}}=31.83\text{Hz}$