MCQ
The position coordinates of a projectile projected from ground on a certain planet (with no atmosphere) are given by $y=\left(4 t-2 t^2\right) m$ and $x =(3 t)$ metre, where $t$ is in second and point of projection is taken as origin. The angle of projection of projectile with vertical is .........
  • A
    $30$
  • $37$
  • C
    $45$
  • D
    $60$

Answer

Correct option: B.
$37$
b
(b)

$y=4 t-2 t^2$

$x=3 t$

$V=V_{x \hat{i}}+V_{y \hat{j}}$

$V_x=\frac{d x}{d t}, V_y=\frac{d y}{d t}$

$V_x=3, V_y=4-4 t$

for $t=0, V_y=4$

$\tan \theta=\frac{V_y}{V_x}=\frac{4}{3}$

$\theta=53^{\circ}$ with horizontal

With vertical

$\theta=37^{\circ}$

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