Question

The x and y components of a position vector P have numerical values 5 and 6 respectively. Direction and magnitude of vector P are
A. `tan^(-1) ((6)/(5))` and `sqrt(61)`
B. `tan^(-1) ((5)/(6))` and `sqrt(61)`
C. `60^(@)` and 8
D. `30^(@)` and 9

Answer 1

Correct Answer - A
Let P be as shown in the figure, then according to the given information
`P_(x) = 5, P_(y) = 6`
`:. |P| = sqrt(P_(x)^(2) +P_(y)^(2)) = sqrt(25+36)`
`rArr |P| = sqrt(61)`
And `tan theta = (P_(y))/(P_(x)) = (6)/(5) rArr theta = tan^(-1) ((6)/(5))`
Thus, P having magnitude `sqrt(61)` lies in XY-plane at an angle `tan^(-1) ((6)/(5))` to the x-axis.