Answer:
v = ω R
number of seconds in 24 hrs = 24 * 3600 = 86400 s / da = T (period)
f = 1 / T
ω = 2 Π f = 2 Π / T = 2 Π / 86400
v = 2 Π / 8.64E4 * 6.0E6 = 436 m / s
Check:
S = 2 Π * 6.0E6 = 3.77E7 m/da
S / T = 3.77E7 m/da / 8.64E4 s/da = 436 m / s
Answer:
I₁/I₂ = 1000
Thus, the sound of siren is 1000 times louder than the sound of wolf's howl.
Explanation:
First, we need to calculate the intensity of both the sounds. The formula for sound level is given as:
L = 10 log[I/I₀]
where,
L = Sound Level in dB
I = Intensity of sound
I₀ = Reference intensity = 10⁻¹² W/m²
<u>FOR SOUND OF SIREN:</u>
L = 120 dB
I = I₁ = ?
Therefore,
120 = 10 log[I₁/10⁻¹²]
log[I₁/10⁻¹²] = (120)/10
log[I₁/10⁻¹²] = 12
I₁/10⁻¹² = 10¹²
I₁ = (10¹²)(10⁻¹²)
I₁ = 1
<u>FOR SOUND OF WOLF'S HOWL:</u>
L = 90 dB
I = I₂ = ?
Therefore,
90 = 10 log[I₂/10⁻¹²]
log[I₂/10⁻¹²] = (90)/10
log[I₂/10⁻¹²] = 9
I₂/10⁻¹² = 10⁹
I₂ = (10⁹)(10⁻¹²)
I₂ = 10⁻³
Now, we divide the intensities:
I₁/I₂ = 1/10⁻³
I₁/I₂ = 10³
<u>I₁/I₂ = 1000</u>
<u>Thus, the sound of siren is 1000 times louder than the sound of wolf's howl.</u>
Answer:
1.625 Pounds Explanation:
This is a speed/time graph.
The slope of the graph at each point is the time rate of change of speed
at that point, and THAT's the definition of the magnitude of acceleration.
The slope of the curve is zero at both ' A ' and ' B ', so acceleration is
zero at both of those points.
That seems to be exactly what choice-c says.
