Distance vs Displacement
- Distance is total length traveled by a moving object irrespective of the direction of motion
- Displacement of an object from a reference point O is the linear distance and direction of the object from O

Speed vs Velocity
- Speed is the rate of change of distance with respect to time
- Velocity is the rate of change of displacement with respect to time
- Instantaneous speed/ velocity = gradient of the point in distance/displacement - time graph

Acceleration
- Acceleration is the rate of change of velocity with respect to time
- Instantaneous acceleration = gradient of the point in velocity - time graph

Description of Motion in graph
a) Distance/Displacement - Time Graph
- Gradient of a straight line connecting two points is the average velocity
- At constant velocity, S-T graph will be a straight line graph

b) Velocity - Time Graph
- Gradient of a straight line connecting two points is the average acceleration
- At constant acceleration, V-T graph will be a straight line graph
- Area under V-T graph is the change in displacement

Equation of Motion
- v = u + at
- s = ut + 1/2 at^2
- v^2 = u^2 + 2as

Free Falling Object
- Object moving only under the influence of gravity
- For flat surface or in the air,
a = g
- For slopes
a = g sin A

Viscous Drag Force
a) No turbulent flow
- Drag Force = kv
b) Turbulent flow
- Drag Force = kv^2

Terminal Velocity
- As drag force increase when velocity increases, net force and hence acceleration of the object will decrease till zero. At this point of time, velocity of object is known as terminal velocity

Projectile Motion
- Motion of an object launched in presence of gravitational field
- Always parabola
- Horizontal motion - u cos A
- Vertical motion - u sin A
- With drag force, motion upwards shorter than motion downwards due to direction of drag force in comparison to weight