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Phy-XI-4-5 unit vectors
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Concept of unit vectors, its significance and applications are introduced in this lecture

Pradeep Kshetrapal is teaching live on Unacademy Plus

Pradeep Kshetrapal
State topper in school exams, selected in IIT Kharagpur, M.Sc., 30 yrs in teaching.

U
Unacademy user
MS
topic Resolution of vector is not taught
Pradeep Kshetrapal
4 months ago
It is taught. Lecture 4-03 components of a vector is resolution of vectors.
MS
Mamta Singh
4 months ago
projectile motion in different situations
MS
Mamta Singh
4 months ago
projectile motion in different situations
sir if there is two dimensional how can I get magnitude
Pradeep Kshetrapal
7 months ago
By using relation r = root a*2 + b*2
please sir discuss ncet problems in this course
  1. PHYSICS Class XI Pradeep Kshetrapal


  2. Chapter 4. Motion in a plain VECTORS Lesson: XI-4-5 Concept of Unit vector


  3. Concept of Unit Vector


  4. Any measurable quantity in Physics is expressed as combination of two identities 1st A standard measurement of its own and 2nd Its multiplier, to show the size.


  5. The quantity Distance- 6 Kilometer give information that 1. Our Unit of measurement is Kilometer (and not- meter, foot or mile) and 2. The distance is 6 times multiplying the standard unit. Note that: Here Kilometer has to have the same nature as of Distance. It can not be mass or time.


  6. Similarly any vector quantity also has an arbitrary unit and a multiplier If I say my position is 5 meters south of origin, then 1 meter towards south is unit in vector but if I say my position is 8 steps south of origin then 1 step towards south is unit in vector. This unit can be made in combination as well. Like A.U., L.Y.


  7. NOTATIONS just like a qty- number x Unit a Vector -number x Unit vector U nu Here is a unit vector of U. As per definition its magnitude is One. Its nature and direction is same as main vector


  8. U=nu Unit Vector it-- and magnitude of vector n =- a = 6a


  9. Universal notations for unit vectors A unit vector in direction of +x is noted as In direction of +y is noted as) -n direction of +Z is noted as k


  10. Here vector Ax is x times unit vector hence it is Axl and its direction is in the X direction. Similarly Ay is y times unit vector hence it is yj and its direction is in the Y direction. Similarly a vector in Z direction Ag can be represented as AA Here Ar, Ay, Ag are magnitude of full vectors Ax , Ay, Az in their respective directions Ay Ayj


  11. Vector A can be written according to triangle rule of additions as B = Bx+ By or By Byj


  12. We can also find out unit vector of any given vector like : find unit vector of A + 2-k Magnitude of given vector is V32 + 22 122v3 Therefore according to relation u- the unit vector is K 2V3