Question

???? plz answers this question guys....

Answer 1

$formula \: to \: be \: used \:$
$p = \sqrt{ {a}^{2} + {b}^{2} + 2ab \cos( \alpha ) }$
$this \: is \: used \: for \: finding \: magnitude \:$
$of \: two \: vectors \: having \: angle \: of \: \alpha$
$between \: them$
$using \: this \: formula$
$we \: have \: to \: find \: magnitude \: of \: 60 \:$
$and \: 30.$

$p = \sqrt{ {30}^{2} + {60}^{2} + 2(30)(60 \cos(60) }$
$so \: p \: = \sqrt{3600 + 900 + 2(30)(60)0.5}$
$hence \: p = \sqrt{6300} = 30 \sqrt{7}$
$as \: there \: are \: i n \: equilbrium \: p \: has \:$
$magnitude \: of \: 30 \sqrt{7}$

$hence \: 30 \sqrt{7} \: is \: the \: answer \:$
$(d) \: is \: the \: correct \: option.$