The mass in the figure slides on a frictionless surface. If m = 2 kg, k1 = 800 N/m and k2 = 500 N/m, the frequency of oscillation (in Hz) is approximately
A)6.
B)2.
C)4.
D)8.
E)10.

Question

The mass in the figure slides on a frictionless surface. If m = 2 kg, k1 = 800 N/m and k2 = 500 N/m, the frequency of oscillation (in Hz) is approximately ​  ​
A)6. 
B)2. 
C)4. 
D)8. 
E)10.

Quizplus · Accepted Answer

The frequency of oscillation is given by $f=\frac{1}{2\pi}\sqrt{\frac{k}{m}}$, where $k$ is the effective spring constant. The effective spring constant for the system is given by $k_{eff}=k_1+k_2=\ 1300	ext{ N/m}$. Therefore, we get $f=\frac{1}{2\pi}\sqrt{\frac{1300}{2}}\approx 4$ Hz. Thus, the answer is choice C.

The Mass in the Figure Slides on a Frictionless Surface