Answer:
It takes 3.31 s for the boy to hear the returning sound of the stone
Explanation:
Ok, the time after which splash is heard is equal to the time acquired by the stone to reach the ground + time taken by sound to return.
First, u=0 m/s (this is the initial speed with which the stone was thrown), h=50 m (is the height of the tower) and g=10 m/[tex]s^{2}[/tex] (is the gravity)
We can use this equation that relates the free fall of the object:
[tex]h=u+\frac{1}{2} gt^{2}[/tex]
[tex]50=0+\frac{1}{2}(10)t^{2}[/tex]
[tex]50=5t^{2}[/tex]
[tex]10=t^{2}[/tex]
and [tex]t=\sqrt{10}=3.16 s[/tex]
t =3.16 s is the time it takes the stone to fall
Second, h=50 m and v=340 m/s (that it's the speed of sound)
We can use this equation:
[tex]h=vt[/tex]
[tex]t=\frac{h}{v}[/tex]
[tex]t=\frac{50}{340}=0,15 s[/tex]
t=0.15 is the time it takes for the sound to return
Finally, both times are added, obtaining the time in which the boy will hear the returning sound of the stone:
[tex]t= 3.16 s + 0.15s[/tex][tex]=3.31 s[/tex]
