A shadow forms on the side of an object that faces away from the sun. The length of shadows changes as Earth rotates. In the morning, the sun is low in the eastern sky and shadows are long. As time passes in the morning, the sun seems to move higher in the sky.
It must have a medium. It must travel in empty space. Mechanical waves are waves which needs medium of propogation.
Answer:
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Answer:
Explanation:
The hippopotamus hearing threshold is 100dB
β = 100 dB
The threshold of human hearing is Io = 1 × 10^-12 W/m²
The sound intensity level is given as
β = 10•Log(I / Io)
100 = 10•Log(I / Io)
Divided Both sides by 10
100 / 10 = Log(I / Io)
10 = Log(I / Io)
Take inverse Logarithm ( antilog) of both sides
10^10 = 10^[Log(I / Io)]
10^10 = I / Io
Then,
I = 10^10 × Io
I = 10^10 × 1 × 10^-12
I = 1 × 10^-2 W/m²
I = 0.01 W/m²
The sound intensity is 0.01 W/m²