Answer:
11.6 m
Explanation:
First of all, we need to calculate the time of flight of the stone. This can be done by analyzing the horizontal motion only, which is a uniform motion with constant velocity [tex]v_x = 3.5 m/s[/tex]. The time of flight is:
[tex]t=\frac{d}{v_x}[/tex]
where d = 5.4 m is the horizontal distance covered by the stone. Substituting,
[tex]t=\frac{5.4}{3.5}=1.54 s[/tex]
Now we can analyze the vertical motion, which is a uniform accelerated motion with constant acceleration g = 9.8 m/s^2 downward. The vertical distance covered (which is the height of the bridge) is
[tex]h=ut+\frac{1}{2}gt^2[/tex]
where
u = 0 is the initial vertical velocity
t = 1.54 s is the time of flight
Substituting, we find
[tex]h=0+\frac{1}{2}(9.8)(1.54)^2=11.6 m[/tex]
