Question

The equation of trajectory of a projectile is
$y=10x-⟮\frac{5}{9}⟯x^2$ If we assume $g=10m{s}^{-2}$, the range of projectile (in metres) is:

• A. 36
• B. 24
• C. 18
• D. 9

Answer 1

The correct option is C 18

The equation of trajectory of a projectile is

$y=10x-\frac{5}{9}{x}^2$

For the range of projectile,

$x=R$ and $y=0$

$0=10R-\frac{5}{9}{R}^2$

$R(10-\frac{5}{9}R)=0$

$10-\frac{5}{9}R=0$

$5R=10\times 9$

$R=18m$

The correct option is C.