Kinematics describes motion without analyzing the forces causing it. It deals with displacement, velocity, acceleration, and time. There are two main categories covered: rectilinear (1D) and projectile (2D) motion.
Rectilinear Motion uses the three SUVAT equations (valid only for constant acceleration): v = u + at, s = ut + \frac{1}{2}$$at^2, and = + 2as. The displacement in the nth second is = u + a. For variable acceleration, calculus is essential: v = , a = = v.
Projectile Motion decomposes into independent horizontal ( = 0) and vertical ( = -g) components. Key results: Time of flight T = 2usin, Maximum height H = sin^2$$\frac{theta}{(2g)}, Range R = *sin. Maximum range occurs at theta = 45 degrees. Complementary angles give equal range but different heights and flight times.
Relative Motion uses = - . River crossing problems require vector decomposition of swimmer/boat velocity.
Graph Analysis connects position, velocity, and acceleration through slopes (derivatives) and areas (integrals). The slope of x-t gives velocity; area under v-t gives displacement.
Key JEE traps include: confusing distance with displacement, forgetting sign conventions, assuming a = 0 when v = 0, and using SUVAT for variable acceleration.