The height y and the distance x along the

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The height $y$ and the distance $x$ along the horizontal plane of a projectile on a certain planet (with no surrounding atmosphere) are given by $y = (8t - 5{t^2})$ meter and $x = 6t\, meter$, where $t$ is in second. the angle with the horizontal at which the projectile was projected is

A

${\tan ^{ - 1}}(3/4$)

B

${\tan ^{ - 1}}(4/3)$

C

${\sin ^{ - 1}}(3/4$)

D

Not obtainable from the given data

The height $y$ and the distance $x$ along the horizontal plane of a projectile on a certain planet (with no surrounding atmosphere) are given by $y = (8t - 5{t^2})$ meter and $x = 6t\, meter$, where $t$ is in second. the angle with the horizontal at which the projectile was projected is

${v_y} = \frac{{dy}}{{dt}} = 8 - 10t$, ${v_x} = \frac{{dx}}{{dt}} = 6$

at the time of projection i.e. ${v_y} = \frac{{dy}}{{dt}} = 8$and ${v_x} = 6$

The angle of projection is given by $\theta = {\tan ^{ - 1}}\left( {\frac{{{v_y}}}{{{v_x}}}} \right) $

$= {\tan ^{ - 1}}\left( {\frac{4}{3}} \right)$