Answer:
1.71
Step-by-step explanation:
the parabolic movment is described by the following equation:
![y = tan(a)x-(1)/(2v_0^2(cos(a))^2)gx^2](https://img.qammunity.org/2020/formulas/physics/high-school/ettf8yndubsk78d8p66mjx3x30mg3kh8xy.png)
where y is the height of the ball, a is the angle of launch,
the initial velocity, g the gravity and x is the horizontal distance of the ball.
So, if we want that the ball reach the hood, we will replace values on the equation as:
![0.8 = tan(47)(5)-(1)/(2v_0^2(cos(47))^2)(9.8)(5)^2](https://img.qammunity.org/2020/formulas/physics/high-school/79k6ibp1mibkikfpsg4k9xoxqixqv48ugx.png)
Finally, solving for
, we get:
![v_0=\sqrt{(-9.8(5)^2)/((0.8-tan(47)(5))2cos^2(47))}](https://img.qammunity.org/2020/formulas/physics/high-school/9l4mw4s16fuqmf7bbtumalwdjtxkzsa51u.png)
1.71