1.

Find V2lal+lbl if sum of given vecctors is 28. Find thFinon blon vectors iszero:(1) 10(2) 20(3) 30(g=145°10(4) 0

Answer»

on balancing horz and vertical ,

b = acos(45°)=> b = a/√2

and asin(45) = 10 => a/√2 = 10 => a = 10√2

so, b = a/√2 = 10

so √2|a|+|b|= √2|10√2| +|10| = 20+10 = 30

option 3

30 or 20?

option 3 is correct

but 10+10 is 20 not 30

it is asked √2|a| +|b| , and a. = 10√2 and b = 10

value of a is 10√2 and not 10/√2 ,

you have taken a as 10/√2 but it is 10√2.

it can't be lesser than 10√2 , otherwise how can its component will balance 10, if it itself is smaller than 10.

it will always be greater than 10.

thannx


Discussion

No Comment Found

Related InterviewSolutions