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Vector Algebra

Question
CBSEENMA12034200
Wired Faculty App

Find the sine of the angle between the vectors
straight a with rightwards arrow on top space equals space 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top space and space straight b with rightwards arrow on top space equals 3 space straight i with hat on top space plus space 4 space straight j with hat on top space minus space 5 space straight k with hat on top

Solution
straight a with rightwards arrow on top space equals space 2 space straight i with hat on top space minus space 3 space straight j with hat on top space plus space 4 space straight k with hat on top comma space space space space straight b with rightwards arrow on top space equals space 3 straight i with hat on top space plus space 4 straight j with hat on top space minus space 5 straight k with hat on top therefore space space space space straight a with rightwards arrow on top space cross times space straight b with rightwards arrow on top space equals space open vertical bar table row cell straight i with hat on top end cell cell space straight j with hat on top end cell cell straight k with hat on top end cell row 2 cell negative 3 end cell 4 row 3 4 cell negative 5 end cell end table close vertical bar space space space space space space space space space space space space space space space space space space space equals space left parenthesis 15 minus 16 right parenthesis straight i with hat on top space minus space left parenthesis negative 10 minus 12 right parenthesis space straight j with hat on top space plus space left parenthesis 8 plus 9 right parenthesis space straight k with hat on top space equals space minus straight i with hat on top plus 22 space straight j with hat on top space plus 17 space straight k with hat on top therefore space space space space space open vertical bar straight a with rightwards arrow on top space cross times space straight b with rightwards arrow on top close vertical bar space equals space square root of left parenthesis negative 1 right parenthesis squared plus left parenthesis 22 right parenthesis squared plus left parenthesis 17 right parenthesis squared end root space equals space square root of 1 plus 484 plus 289 end root space equals square root of 774 space space space space space space space space space space space space space space space space space space space space space space space space equals space square root of 9 space cross times space 86 end root space space space equals space 3 square root of 86 space space space space space space space space space space space space space space space space space space space straight a space equals space square root of 4 plus 9 plus 16 end root space space equals space square root of 29 comma space space space straight b space equals space square root of 9 plus 16 plus 25 end root space space equals space square root of 50 space equals space square root of 25 space cross times 2 end root space space space equals space 5 space square root of 2 space Now space open vertical bar straight a with rightwards arrow on top cross times space straight b with rightwards arrow on top close vertical bar space space equals space straight a space straight b space sin space straight theta comma space space where space straight theta space is space angle space between space straight a with rightwards arrow on top space and space straight b with rightwards arrow on top therefore space 3 square root of 86 space space equals space left parenthesis square root of 29 right parenthesis thin space left parenthesis 5 square root of 2 right parenthesis space sin space straight theta space space space space space rightwards double arrow space space space sin space straight theta space equals space fraction numerator 3 square root of 86 over denominator 5 square root of 58 end fraction

Some More Questions From Vector Algebra Chapter

Classify the following measures as scalars and vectors.
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(ii) 1000 cm3
(iii) 10 Newton
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(v) 10 g/cm3
(vi) 20 m/s towards north

Classify the following measures as scalars and vectors.
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Classify the following measures as scalars and vectors.
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