## A thought provoking (HOTS) problem from rotation

Consider a disk rotating in a horizontal plane with a constant angular speed “omega” about its center O.

The disk has a shaded region on one side of the diameter and an unshaded region on the other side.

When disk is in horizontal plane x-y with left half shaded and right half unshaded, two pebbles P and Q are simultaneously projected at an angle towards R.

The velocity of projection is in the y-z plane and is same for both pebbles with respect to the disk.

Assume that

(i) they land back on the disk before the disk has completed one-eighth rotation,

(ii) their range is less than half the disk radius,and

(iii)”omega” remains constant throughout.

**Then where will the two pebbles land?**

*(All are invited to answer this)*

## A doubt from Dimensional Analysis

What about the correctness about the relation,

s_{t}=u+0.5a(2t-1), both dimensionally or any other

Prakash Adhikari asked

**Answer**

The equation refers to the displacement in the **t ^{th} second** and hence it should have the dimensions of speed; since it is the

**displacement in one second**.

Under this consideration, the equation is dimensionally and otherwise correct.

## Thoughts on Higgs Boson

When it is not contested scientifically that change is a continuous phenomenon,how is that **Higgs boson**, if found,can be considered as the ultimate building block of matter.

Sure, it may prove a mathematically arrived conclusion… yet the contradiction remains.

An ever changing, at the same time, ever stable (because it is the ultimate one) is the contradiction.

One may find changing or divisible particle only…

(Posted by K.C. Muralidhar)

**Please post your thoughts and reactions as comments to this post**