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
I am going to say
C. Energy contained in the nucleus of an atom
The answer is 4.0 kg since the flywheel comes to rest the
kinetic energy of the wheel in motion is spent doing the work. Using the
formula KE = (1/2) I w².
Given the following:
I = the moment of inertia about the
axis passing through the center of the wheel; w = angular velocity ; for the
solid disk as I = mr² / 2 so KE = (1/4) mr²w². Now initially, the wheel is spinning
at 500 rpm so w = 500 * (2*pi / 60) rad / sec = 52.36 rad / sec.
The radius = 1.2 m and KE = 3900 J
3900 J = (1/4) m (1.2)² (52.36)²
m = 3900 J / (0.25) (1.2)² (52.36)²
m = 3.95151 ≈ 4.00 kg
Quantitative because it tells you how many wheels
