Sound at 70 dB is 70 dB louder than the human reference level. That's 10⁷ times as much as the reference sound power.
Sound at 73 dB is 73 dB louder than the human reference level. That's 10⁷.³ or 2 x 10⁷ times as much as the reference sound power.
Sound at 80 dB is 80 dB louder than the human reference level. That's 10⁸ or 10 x 10⁷ times as much as the reference sound power.
Now we can adumup:
Intensity of all 3 sources = (10⁷) + (2 x 10⁷) + (10 x 10⁷)
Intensity = (13 x 10⁷) times the sound power reference intensity.
Intensity in dB = 10 log (13 x 10⁷) = 10 (7 + log(13)
Intensity = 70 + 10 log(13)
Intensity = 70 + 10 (1.114)
Intensity = 70 + 11.14
Intensity = <em>81.14 dB</em>
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Looking at the questioner's profile, I seriously wonder whether I'll ever get a comment in return from this creature, and how I'll ever find out if my solution is correct. For that matter, I'm also seriously questioning how and whether my solution will ever be used for anything.
Answer:
b- a bicycle sitting on the ground
Explanation:
'Static' means it's not moving.
So, only the answer listed as "a bicycle sitting on the ground" corresponds to that condition.
All others possible answers describe something that is moving (an apple falling, a motorcycle accelerating, a car moving at a constant speed). Even if they are going at a constant speed, they are moving, so not static.
The distance between the two cities is 513.24 km.
<h3>Time of motion when the two trains meet</h3>
The time spent on the journey when the two trains meet is calculated as follows;
(Va - Vb)t = d
where;
- d is the distance between the trains before meeting
(76 - 65)t = 40
11t = 40
t = 40/11
t = 3.64 hr
<h3>Distance traveled by the fast train</h3>
d1 = 76 km/h x 3.64 h
d1 = 276.64 km
<h3>Distance traveled by the slow train</h3>
d2 = 65 km/h x 3.64 h
d2 = 236.6 km
The distance between the two cities = 276.64 km + 236.6 km
= 513.24 km
Learn more about relative velocity here: brainly.com/question/17228388
Answer:
90 hp
Explanation:
Power = work / time
P = ½ (1500 kg) (25 m/s)² / 7.0 s
P = 67,000 W
P = 90 hp
Answer:
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
Explanation:
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