Simple Harmonic Motion 3 Question 8

8. A highly rigid cubical block A of small mass M and side L is fixed rigidly on to another cubical block B of the same dimensions and of low modulus of rigidity η such that the lower face of A completely covers the upper face of B. The lower face of B is rigidly held on a horizontal surface. A small force F is applied perpendicular to one of the side faces of A. After the force is withdrawn, block A executes small oscillations, the time period of which is given by

(a) 2πMηL

(b) 2πMηL

(c) 2πMLη

(d) 2πMηL

(1992,2M)

Show Answer

Answer:

Correct Answer: 8. (d)

Solution:

  1. Modulus of rigidity, η=F/Aθ

Here,

A=L2

and

θ=xL

Therefore, restoring force is

F=ηAθ=ηLx

or acceleration, a=FM=ηLMx

Since, ax, oscillations are simple harmonic in nature, time period of which is given by

T=2π displacement  acceleration =2πxa=2πMηL



जेईई के लिए मॉक टेस्ट

एनसीईआरटी अध्याय वीडियो समाधान

दोहरा फलक