Answer:
49.4 m
Explanation:
u = 25 m/s
θ = 52°
y = 12 m
Let the distance between the cannon and the building is d.
Use the general equation of projectile path
[tex]y = d tan\theta -\frac{gd^{2}}{2u^{2}Cos^{2}\theta }[/tex]
By substituting the values, we get
[tex]12= d tan52 -\frac{9.8\times d^{2}}{2\times 25 \times 25Cos^{2}52[/tex]
[tex]12=1.28 d -0.021 d^{2}[/tex]
[tex]0.021 d^{2}-1.28d+12= 0[/tex]
[tex]d=\frac{1.28\pm \sqrt{1.64-1.008}}{0.042}[/tex]
d = 49.4 m