As shown in the figure, an iron block A of volume 0 . 25   m 3 is attached to a spring S of unstretched…

As shown in the figure, an iron block A of volume 0.25 m3 is attached to a spring S of unstretched length 1.0 m and hanging to the ceiling of a roof. The spring gets stretched by 0.2 m. This block is removed and another block B of iron of volume 0.75 m3 is now attached to the same spring and kept on a frictionless incline plane of 30° inclination. The distance of the block from the top along the incline at equilibrium is

  1. 1.1 m
  2. 1.3 m
  3. 1.6 m
  4. 1.9 m

Solution

The free body diagrams of the blocks are shown in the figure below.

At equilibrium, the net force on a body is zero. Therefore,

For block A,

mAg=kxk=mAgx

And for block B,

mBgsin30°=kx'x'=mBg2mAgx

Since the same material is used for both the blocks, their masses will be proportional to their volume.

x'=VB2VAx=0.752×0.25×0.2=0.3 m.

Therefore, the distance of block B from the top is d=l+x'=1.3 m.

Asked in: AP EAMCET 2022 (04 Jul Shift 2)

Practice more Oscillations questions on Aicharya