This book has been conceptualized as per the recommended National Education Policy (NEP) 2020 and as per the syllabus prescribed by the University of Delhi for B. Sc. Students of Physics for the First Semester. It covers important topics such as Reference Frames and Mechanics of Centre of Mass, Work and Energy, Collisions, Dynamics of a Rigid Body, Newton's Law of Gravitation, Motion Under Central Force Field, Simple Harmonic, Damped and Forced Oscillations and Non-Inertial Frame: Fictitious Forces for strong conceptual understanding. It also contains "First Step in Laboratory" which engages the learner to understand laboratory experiments in a clearer fashion.