Answer:
Distance = 16.9 m
Explanation:
We are given;
Power; P = 70 W
Intensity; I = 0.0195 W/m²
Now, for a spherical sound wave, the intensity in the radial direction is expressed as a function of distance r from the center of the sphere and is given by the expression;
I = Power/Unit area = P/(4πr²)
where;
P is the sound power
r is the distance.
Thus;
Making r the subject, we have;
r² = P/4πI
r = √(P/4πI)
r = √(70/(4π*0.0195))
r = √285.6627
r = 16.9 m
<span>Radioactivity is the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei. Particles are emitted from the nuclei as a result of nuclear instability.
</span><span>
The radioactivity of an atom is dependent on the difference in binding energy .</span>
(comparing the before and after states, the binding energy of the <span>product nucleus and the binding energy of the initial decaying nucleus)</span>
Answer:
2.5 cm
40 D
Explanation:
When the radius of curvature of a lens is divided by 2 we get the focal length of the lens.
Focal length is given by

The focal length of the lens is 2.5 cm
When we divide 1 by the focal length in the unit of meters we get the power of a lens
Power of a lens is given by

The power of the lens is 40 D
Answer:The answer is B , 0.20 m/s south
Explanation:
The smallest one is the least powerful one. And the medium size one is the medium powerful one. And the largest one is the most powerful one of them all