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MOTION IN A STRAIGHT LINE, E GSH, [G5H], INTRODUCTION: Molion of object ig -Pamiliar to one and all|, a nd is common to everything in the universe. The examples, f motion în everyday life gre : the water -Palling down a, dam, a running train , the blowing air, a bird Flying in air,, a car moving on a road, the crooling în secs, Ihe leaues, |-talling from trees,the rolation of the eorth aboul ls, axi 5, the revolution of the planets around the sun. when, an object is in motion, the n ils posiion chanqes with the, passage of time. For learning the descriplion of motion,, -the concepls of displace ment, velocity, 'relative velocity,, acceleration' are developed. This unit is contined to the, study of molion of objects a long a straight line, crectilinear motlion). -A sel of simple equations can be, oblained for -lhe case of reclilinear with unitorm, acceleralion., Mechanies:The branch of physics which deals with the, of motion of material objects is called Mechanics., Mechanics îs broadly classified înto., 1> statics, 2) Kinematics, 3) Dynamics., 1? STATICS:The branch of mechanics which deals wilh, the study of material objects is called slalics ., 2) KINEMATIS: The branch of mechanics which deals, with -he study of motion of mma terial objects withourl, taking into consideration the factors uohich cause of, motion is ca lled Kinematics., 3)DVNAMICS:The branch of mechanics which deals, with the sludy of motion of objects taking iolo, considerationof the tactor which cause motion, 9s called dynamics., 1 Scanned By Scanner Go

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GSH, POINT OBJE CT:1f he size of an, object is very small, in comparison woith the distance travelled by 9t, ihen, -the object ?s said -1o be point object., parlicle is a point mass., REST :A, parlicle is said lo be al resl, if it does not, change Pls postlion with respect lo Hs surroundings, wi-thtime., MOTION: A parlicle is said -lo be în molion, if it changes, 94s position' with respect lo 91s surrounding with time., REST AND MOTION ARE RELATIVE TERMS:, Let us imagine that we are siHing in a, mouing train. We are in moli on with respect-fo a person, standing oulside the train. But if, posilion with respect -lo the things (Hans, wall s, roof, of the train elc) inside the train, then we are at rest., Therefore, an object can be at rest Pn relation to one, object and it can be in molion in relalton lo another, object at the same instan of time. Thu3, rest and, motion are re lative terms., we compare our, TYPES OF MOTION, >ONE DIMENSIONAL MOTION: when a body noves, g a straight line, 91 9s said -lo be in one dimension, a long, |-al motion.cID], EXAMPLES, VIA, > A train mouing along a, 2 A stone dropped from a heigh., straight hack., A, Scanned By Scanner Go

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GSH, PTWO DIMENS1ONAL MOTION : when a body moves in a, plane,, P-1 9s said-lo be in -loo dimensional molion,n caD, EXAMPLES:, The projeclile motion., The circular motion of a body., to, 3THREE DIMENSIONAL MOTION : Vohen a body moves in space,, 94 9s said-lo be în three dimensional motion:[30], EXAMPLES, )A bird flying in the sky, ) A fish moving in an aquarium, FRAME OF REFERENCE : A sustem of co-ordinate axes, or motion of an, objecl 9s descri bed is called' Frame of reterence., object appears, with reference -lo which the posilion, The position or motion of an, -from differenl frames of reference., difterent, Example:, >if an object is released -from an deroplane moving, with uni-form velocity, it appears -lo move' verlically, downward along a straight line with respect -1lo, person in-lhe aeroplane. But H, a para bolic palh wilh respect lo a person on the, ground., TYPES OF FRAME OF REFERENE, appears, -1o, to move, along, )Inerlial ( Non-accelera led) frame of reference., a)Non inertial(accelerated) frame of reference., Scanned By Scanner Go

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GSH, D1STANCE (PATH LENGTH): The length of the actual path, Covered by a parhele i, n a given time interval 86 called distance., Note:, 1. Distance is a scalar quantity., 2. Its SI unit is metre (m), 3. The dimensional -formula ió [MO!T°], 4.IH depe nds on the actual path followed by the parlicle., 5. IH is always posilive and cannot be zcro o7, for a moving par-licle ., negative, DISPLACEMENT: The shortest distance hrave lle d between, n9tial and lhe final positions of the particle in a given, Hime interval is called displacement., Note:, 1. Dis placement is a vector quantily., 2. 1ls SI unit is metre (m), 3.Hs dimensional formula [Mo L'T°], 4-11 does not depend on -he actual path followed by the, particle., positive, zero or negative for a moving particle., displacement., ifference between dislance ond, DISTANCE ( PATH LENGTH), 1. IH is change sin, position of a particle 1.H is change în position ofa particle, in a given time interval without, reference to direclion., DISPLALEMENT, 2.4 depends on actual path., 3.11 is scalar quantity., 4. IH 95 always positive and cannot 4.14 is always be positive,, Rn a given time interval uwith Te ference, Ho direction., 2.14 does not depend on actual path., 5. 14 is vector quantity., negalive or zero Tor mouing, particle., 5.It is equalHo or less than, distance. cannot be grealer, stanned By Scaħner Go, 5, negative dor moving, be zero or, particle., 5. H 95 equal OY greater than, displacement, but cannot be, less than displacement.