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PHYSICS EDUCATION MOTION A Comprehensive Study Guide with Numericals Introduction to Motion Defining change in position with respect to a frame of reference. Types of Motion a of © Uniform Motion Non-Uniform Motion Key Point When a body covers equal When a body covers unequal Most real-life motions (like distances in equal intervals of distances in equal intervals of traffic) are non-uniform. time. time. Scalar Quantities Physical quantities that have magnitude only are called scalar quantities. e Examples: Mass, Energy, Speed, Time, Distance e They are added using simple arithmetic. S Glenn Scalars and Vectors — Reseach A scalar quantity has only magnitude. A vector quantity has both magnitude and direction. Scalar Quantities Vector Quantities length, area, volume displacement mend ieee mass, density Pn pressure momentum temperature force energy, entropy lift , drag , thrust work, power weight Distance The length of the path covered by a body in a plane is called distance. o |Itis ascalar quantity. o |tis always positive. o §.]. Unit: Meter (m) Displacement The shortest distance between final and initial positions of an object. Magnitude of displacement can never be greater than distance. Can be Displacement (When back to starting point) Acceleration Acceleration is the rate of change of velocity with time. see eB BB BB BB Bw BB BB BB BB BB eB BB BT eB Be BB BB BB BB eB TB BB BB BB BB BB BB BB BB BB BB BB Be BB BB BB BB BB TP BP BB BB Be eB BB eB BB ee Be BBB BB BB BB BB TB TB BB SB Zw EZ EZ EK KL eee @ u: Initial Velocity @ v: Final Velocity @ S.l. Unit: m/s” Retardation Negative Acceleration When velocity decreases, acceleration is negative. This is called Retardation. Example: Applying brakes to stop a moving car. Deriving Ist Equation From definition of acceleration: Fe et rete NE Eh lel el ial a= Vv u Mutiphingttobothsides; teveU Rearranging: v=urat Deriving 2nd Equation Distance = Average Velocity x Time FN ete ett et et ea te ee i — x cr Oe ee ee ee ee ee ee ee ee ee ee eumeeeeee eee ee ee ee ee ee ewe ee eee eee eee eee eee eee eee eee ee ee eee eee eee eee eee eee ee eee eee eee eee eee eee eee eee eee eee eB EA ! +ut | | s= (= u aby) x f ! ! 2 ! Results in: 2 s = ut + Jat Numerical: Racing Car Problem: Car starts from rest, acceleration = 4 m/s’. Distance covered in 10s? Given: u=O, a=4, t=10 Fe A ee ee ee I Answer: Distance = 200 m pixtastock.com - 117604 Numerical: Retardation Problem: Car at 10 m/s stops in 20s. Find retardation. u= 10 m/s, v=0,t=20s SU=105 | 2 a 0 0.5 m/s Retardation = 0.5 m/s? Important Questions Short: Difference between distance and displacement. Distance is path length (Scalar); Displacement is shortest gap (Vector). Long: Derive the 3rd equation of motion. Combine V = U + atandS = ul + lat* by eliminating time (t). THANK YOU Master the Concepts of Motion Study Hard | Solve Numericals | Clear Doubts 
