Question

If the initial velocity in horizontal direction of a projectile is unit vector $\hat i$ and the equation of trajectory is $y = 5x(1 – x)$. The y component vector of the initial velocity is ______ $\hat j$.
(Take $g=10\ m/s^2$)

Answer 1

$y=5x–5x^2$
$y=x\ tan\ θ–\frac 12 \frac {gx^2}{v^2}$
$tan⁡θ=5=\frac {u_y}{u_x}$
$⇒u_y=5$

So, the correct option is $5$.