Inelastic Collisions — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Inelastic Collisions.

Perfectly Inelastic Collision with Energy Loss Calculation

high

This is a perennial favorite. Questions will involve two masses colliding and sticking together, asking for the common final velocity or, more commonly, the kinetic energy lost. The direct formula for maximum kinetic energy loss is a quick way to solve these, making it a good test of formula recall and application. Students often make sign errors or calculation mistakes in these problems, making them effective discriminators.

Bullet-Block Pendulum (Two-Stage Problem)

high

This problem type combines conservation of momentum (perfectly inelastic collision) with conservation of mechanical energy (swinging motion). It tests a student's ability to apply different conservation laws to different phases of a single event. Expect variations where the block might be on a frictionless surface or suspended, and questions about initial bullet velocity, final height, or tension in the string.

Conceptual Questions on Coefficient of Restitution (e)

medium

NEET often includes conceptual questions to check fundamental understanding. Questions might ask about the range of 'e' for inelastic collisions, what $e=0$ signifies, or how 'e' relates to the relative velocities of approach and separation. These are quick to answer if the concept is clear, but traps can be set by mixing up definitions with elastic collisions.

General Inelastic Collision with 'e' given

medium

Problems where $0 < e < 1$ require solving two simultaneous equations (momentum conservation and the 'e' equation) to find the final velocities of both objects. This tests algebraic skills and careful application of vector signs. While slightly more involved than perfectly inelastic cases, they are a good test of comprehensive understanding of inelastic collisions.