Known variables
d=4.6m
initial velocity=0m/s
downward acceleration=-9.8m/s2
d=1/2gt2
4.6=1/2 -9.8 t2
t=0.93s
The sound was repeated because of the phenomenon of echo. The speed of sound in the metal is 800 m/s.
Echo results from the reflection of sound waves. The reason why a sound may be heard twice owes to the phenomenon of reflection which leads to echo.
To determine the speed of sound in the metal;
Length of metal = 1000 m
Time taken between the two sounds = 2.5 s
Using the formula;
V = 2d/t
V = 2(1000)/2.5
V = 800 m/s
The moments to the left of the pivot must be equal to the moments on the right. Let d represent the distance of each mass from the pivot, which is at the 50 cm mark.
md₁ + md₂ = md₃ + md₄
m cancels out from both sides,
d₁ + d₂ - d₃ = d₄
(50 - 27) + (50 - 38) - (99 - 50) = d₄
d₄ = -14
That means the mass should be placed 14 cm to the left of the pivot, at the 36 cm mark.
Answer:
Hope this solution helps you
