Will this one work?...................
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.
Answer:
The values is 
The direction is out of the plane
Explanation:
From the question we are told that
The magnitude of the electric field is 
The magnitude of the magnetic field is mathematically represented as

where c is the speed of light with value


Given that the direction off the electromagnetic wave( c ) is northward(y-plane ) and the electric field(E) is eastward(x-plane ) then the magnetic field will be acting in the out of the page (z-plane )
Answer:
Explanation:
F = kQq/r²
r = √(kQq/F)
a) r = √(8.899(10⁹)(8)(4) / 18(10¹³)) = 0.0397749... m
r = 40 mm
b) r = √(8.899(10⁹)(12)(3) / 18(10¹³)) = 0.0421876... m
r = 42 mm