Mechanics

Source of my notes

● Mathocrat videos
● IMS notes

My take on the chapter

Mechanics is an interesting chapter, especially if you have interest in Physics and remember
the basics from Class 11 Physics. A short go through the chapter on Rotation from “HC
Verma Concepts of Physics(Vol-1)” can help you recall the concepts. In any case, I believe
that Shivraj Gurjar Sir has covered the chapter pretty well on his YouTube Channel
Mathocrat.

You can divide this chapter in two parts :

1. Rotation and Translation
○ This is mostly related to your prior knowledge from Class 11. Basic concepts
of Moment of Inertia, Force, Torque, Rolling motion, Rolling with Sliding needs
a brush up. Initially recalling all of these may take time. But once done, unlike
other chapters, this stays with you till the end.

2. Lagrangian and Hamiltonian Equations

○ This is something new for most of the aspirants. But a question is guaranteed
from these equations every year. Mathocrat has explained these in as simple
terms as it can be. They are sufficient for you to write the equations for all the
common problems(Only the common problems are asked in the exams), for
eg - Projectile motion, Pulley with two objects, Object on an inclined plane
etc.

Overall I believe that practising Mechanics could help you reduce the risk of being stuck in
tougher questions from Modern Algebra. Section-B of Paper 2 should be given extra focus
due to the nature of the chapters here. PDE, Numerical Analysis and Mechanics(along with
basics of Fluid Dynamics) could give you the confidence to attempt two questions from
Section-B. Section-A has the risk of tougher problems from Modern Algebra and lengthy
questions from Linear Programming. I would thus advise everyone to not ignore Mechanics
and Fluid Dynamics. It could be the game changer for you, as it was for me.

All the best !!

Utsav Anand
AIR-26, UPSC CSE-2021
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