Question

The distance PQ. (Take $g=10m/s^2$)

Answer 1

Given : $u=u_x=10\sqrt{3}$ $m/s$ $u_y=0$

$a_x=-gsin{60}^o=-5\sqrt{3}$ $m/s^2$ (solved earlier)

Also the time of flight $t=2$ s (solved earlier)

x direction :

Using $S_x=u_{x}t+\frac{1}{2}{a}_x{t}^2$ where $t=2$ s

$\therefore$ $S_x=\left(10\sqrt{3}\right)\times 2-\frac{1}{2}\times 5\sqrt{3}\times 2^2=10\sqrt{3}$ m

Also $|S_y|=10$ m (solved earlier)

$\therefore$ Distance PQ $PQ=\sqrt{(S_y{)}^2+(S_x{)}^2}=\sqrt{(10{)}^2+(10\sqrt{3}{)}^2}=\sqrt{400}=20$ m