Misc 3 - A girl walks 4 km west, then 3 km 30 east of north - Addition(resultant) of vectors

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  1. Chapter 10 Class 12 Vector Algebra
  2. Serial order wise
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Misc 3 A girl walks 4 km towards west, then she walks 3 km in a direction 30 east of north and stops. Determine the girl s displacement from her initial point of departure. Let initial point of departure be O(0, 0) & OA = 4km AB = 3km XAB = 30 We need to find OB Now, BAO = 90 XAB = 90 30 = 60 Let us draw BD OA Now, OD = OA AD OD = 4 = = Now, In right triangle BDO Hypotenuse2 = Base2 + Height2 OB2 = OD2 + BD2 OB2 = 5 2 2 + 3 3 2 2 OB2 = 25 4 + 3 2 3 2 2 2 OB2 = 25 4 + 9 3 4 OB2 = 25 4 + 27 4 OB2 = 52 4 OB2 = 13 OB = 13 Therefore, the displacement of the girl from her initial point of departure is km.

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Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.