Chapter at a glance
How to describe motion: position, distance and displacement, speed, velocity and acceleration, motion graphs, the kinematic equations, and motion in a plane including uniform circular motion.
What this chapter covers
- 4.1 Motion in a Straight Line
- 4.2 Graphical Representation of Motion
- 4.3 Kinematic Equations for Motion in a Straight Line
- 4.4 Motion in a Plane
Key points
- Displacement is the net change in position; average speed = total distance ÷ time; average velocity = displacement ÷ time.
- Average acceleration = change in velocity ÷ time.
- For constant acceleration: v = u + at, s = ut + ½at², v² = u² + 2as.
- Motion in a circle at constant speed is uniform circular motion.
Read the NCERT chapter
Read this chapter in the official NCERT textbook Exploration (2026-27 edition) for free on ncert.nic.in.
Source: NCERT, Exploration, Grade 9 (2026-27). NCERT chapter PDF. Spotted a mistake? Email edura.class9.yt@gmail.com. Last updated 11 October 2026.