Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,
where;
the threshold of hearing
I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W
Answer:
The answer is 0.83 seconds.
Explanation:
The formula of free fall is following:
Where g=9.8 m/s^2 and t=2 seconds, the rock takes:
19.6 meters. This is the half distance of the cliff. The whole distance is 39.2 meters. So it takes:
2.83 second to fall down completely. The rock takes the second half of the cliff in 0.83 seconds