Motion in a Straight Line

Beginner

Topper

Chapter 3 is straight line motion only. No circle, no zig-zag. Just forward-backward. Like Metro on straight track. This is called rectilinear motion - 1D motion.

Rectilinear = 1D straight line motion.

1. Frame of Reference

Rest and motion are relative. In metro you are at rest for person next to you, moving 60 km/h for friend at station. So need origin + axes + clock = frame.

2. Path Length vs Displacement

Distance vs Displacement

Home to market straight 1km, you went via Sec 18 total 1.5km. Path length = 1.5 actual, displacement = 1 straight. Watch shows distance, exam asks displacement.

3. Average Speed vs Velocity

Avg Speed vs Avg Velocity

4. Graphs

x-t & v-t Graphs - Handwritten

5. Acceleration - Metro Phases

Acceleration Phases - Metro

6. Kinematic Equations

3 Golden Equations

7. Free Fall & Stopping Distance

Free Fall & Braking

8. Relative Velocity

Relative & Rain Umbrella

Gold Reference - Chapter 3

Concept	Formula	Example
Displacement	x2-x1	Return 0
Avg Speed	distance/time	12km/h
v-t area	Area=disp	Board fav
Equations	v=u+at, s=ut+½at², v²=u²+2as	Free fall