Answer:
250 / 2.5*10^2
Explanation:
What is the difference between mechanical waves and electromagnetic waves?
1 answer:
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Answer:
Explanation:
Energy of signal being radiated per second on all sides = 71 x 10³ J .
At a distance of 220 m it is spread over an area of 4 π x (220)² because it is spreading uniformly on all sides.
So energy crossing per unit area
=
= 11.67 x 10⁻² Wm⁻²s⁻¹.
This is the intensity of the signal.
At 2200 m this intensity will further reduce by 100 times
So there it becomes equal to
11.67 x 10⁻⁴ Wm⁻² s⁻¹.
Answer:
a. If c = 20 cm, then the mass of the brain is m = 5 g.
b. At c = 20 cm, the brain's mass is increasing at a rate of 15.75 g/cm.
Explanation:
From the equation
we have
a. for c = 20 cm
then the mass is m(20) = 5 g.
b. In order to find the rate of change, first we derivate
Evaluated at c = 20 cm, we have
So, at c = 20 cm, the mass of the brain is increasing at a rate of 15.75 g/cm.