**1-Rest & motion are relative terms.**

**2-There is no meaning of rest or motion without the viewer.**

**3-Nothing is in absolute rest or in absolute motion.**

**4-For a moving object distance can never decrease with time. Thus for a moving object the (distance/time) curve is strictly increasing.**

**5-Magnitude of displacement vector between two points is the shortest distance between these two points. Hence:-|displacement| ≤ distance**

**6-For a moving particle distance can never decreases with time while displacement can.**

**Decrease in displacement means body is moving towards the initial position.**

**7-The instantaneous velocity is always tangential to the path followed by the particle. Hence:-**

**|instantaneous velocity|= instantaneous speed**

**8-**Velocity** remain constant throughout a given interval of time, the motion is said to be uniform & for uniform motion. V=constant=V(av)**

**However converse may not be true.**

**9-Velocity is constant, speed ( =|velocity| ) will also be constant. However converse may not be true.**

**10-For a given interval average velocity is singled valued, while average speed can have many values depending on path followed.**

**11-For a moving body average speed can never be negative or zero (unless t~infinity), while average velocity can be i.e. V(av) > 0 while v̅ (av) >= or < 0**

**12-Since |displacement| ≤ distance, hence |average velocity| ≤ average speed i.e. Magnitude of average velocity is always less than or equal to average speed for same interval of time.**

**13:-If a particle is moving with uniform acceleration, this doesn’t necessarily imply that particle is moving in straight line.**

**14:-There is no definite relationship between the direction of velocity vector & direction of acceleration vector.**

**Angle between them may have any value.**

**15:-If a body is acted upon by a constant acceleration, it’s path **

**Will be staraigh line if it’s initial velocity is along the line of acceleration****Will be a parabola if it’s initial velocity is making some angle other than zero or 180° with the acceleration.**

**16:-If an object is moving along a straight line, it’s acceleration vector is along the line of motion.**

**17:-In general, the path followed by a particle maybe curved. Then net acceleration of the particle has two **components**.**

**18:-Tangential acceleration is the rate of change of speed i.e.{ a=d|v̅|/dt }**

**Normal acceleration = V^2/r****Where v= speed of particle ; r= radius of curvature of the path.**

**19:-For a body moving with uniform acceleration, we have average acceleration = instantaneous acceleration.**

** THE SLOPE OF MOTION GRAPHS**

** FIGURE:-A **

** MOTION GRAPHS**

** FIGURE:-B**