This can be answered using the beat frequency formula, which is simply the difference between 2 frequencies.
Let: <span>fᵇ = beat frequency
</span>f₁ = first frequency
f₂ = second frequency
fᵇ = |f₁ - f₂|
substituting the values:
fᵇ = |24Hz - 20Hz|
fᵇ = 4Hz
The unit Hz also means beats per second, therefore:
<span>fᵇ = 4 beats per second
</span>
Therefore, the answer is C. 4
'Pressure' is (force) / (area).
The only choice with those units is #1 .
La intensidad de la luz se baja con cada bombillo que agregas
V = [4/3]π r^3 => [dV / dr ] = 4π r^2
[dV/dt] = [dV/dr] * [dr/dt]
[dV/dt] = [4π r^2] * [ dr/ dt]
r = 60 mm, [dr / dt] = 4 mm/s
[dV / dt ] = [4π(60mm)^2] * 4mm/s = 180,955.7 mm/s
Answer:

Explanation:
Let the linear charge density of the charged wire is given as

here we can use Gauss law to find the electric field at a distance r from wire
so here we will assume a Gaussian surface of cylinder shape around the wire
so we have

here we have


so we have
