Question

King Arthur's knights use a catapult to launch a rock from their vantage point on top of the castle wall, 13m above the moat. The rock is launched at a speed of 30m/s and an angle of 40∘ above the horizontal. how far from the castle wall does the rock land?

Answer 1

so you would have to find the time first by using a quadratic equation, the equation is:\[t =\frac{v _{oy}\ }{ g } \pm \sqrt{\frac{ v^2_{oy} }{g^2}- \frac{2y}{g}} \]
then you would substitute all your variables into there, please note that when you sub, the y is negative 13, because thats the distance below the start point.



ok, so now you have your time, you can use the equation to find your distance (x)
\[x = v _{ox} * t\]
then you should have your distance :)