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
Hydraulic conductivity (K) is a property of soil<span> that describes the ease with which water can move through </span>pore<span> spaces. It depends on the permeability of the material (</span>pores, compaction) and on the degree of saturation. Saturated hydraulic conductivity, Ksat<span>, describes water movement through saturated media.</span><span />
sorry - late reply...just stumbled across tis...hope u can still use it :)
By the mirror equation: 1/di + 1/do = 1/f
<span>
</span>
<span>where di = distance to image = +12cm (+ for real image)</span>
and do = distance to object = +8cm
Substitute and solve for f, the focal length
<span><span>
1/12 + 1/8 = 1/f
</span><span>
1/f = (8 + 12) / 12 * 8 = 20/96
</span><span>
so f = 96/20 = 4.8 cm</span>
</span>
Direction and Strength can be measured of force
