Question # The ( X ) and ( Y ) -component of ( vec{P} ) are 7 i and 6 j.

# The ( X ) and ( Y ) -component of ( vec{P} ) are 7 i and 6 j.

Also, the X and Y-components of ( overrightarrow{mathrm{P}}+overrightarrow{mathrm{Q}} ) are ( 11 hat{mathrm{i}} )

and 9 jespectively. Then magnitude of ( overrightarrow{mathrm{Q}} ) is:

(A) 7

(B) 6

(C) 5

(D) 13

Solution

( vec{p}=7 i+6hat{j} )

( vec{O}=a i+b j )

( vec{p}+vec{phi}=11 i+9 j )

( Rightarrow 7 i+6 hat{jmath}+a i+b j=17 i+9 j )

( Rightarrow quad a i+b j=4 i+3 hat{j}=vec{g} )

( begin{aligned} therefore quad|vec{Q}|=& sqrt{3^{2}+4^{2}} &=5 quad text { (c) } operatorname{Ans}end{aligned} )