Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula

I₀ = 10⁻¹² W/m²
now,



to hear the whisper sound = 80 dB



we know intensity of sound is inversely proportional to square of distances



r₂ = 0.2 m
Given :
Two forces act on a 6.00-kg object. One of the forces is 10.0 N.
Acceleration of object 2 m/s².
To Find :
The greatest possible magnitude of the other force.\
Solution :
Let, other force is f.
So, net force, F = 10 + f.
Now, acceleration is given by :

Therefore, the greatest possible magnitude of the other force is 2 N.
Hence, this is the required solution.
The best and most correct answer among the choices provided by the question is <span>a.The Three Laws of Planetary Motion, Principia Astronomica. </span>
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