A)<span>
dQ = ρ(r) * A * dr = ρ0(1 - r/R) (4πr²)dr = 4π * ρ0(r² -
r³/R) dr
which when integrated from 0 to r is
total charge = 4π * ρ0 (r³/3 + r^4/(4R))
and when r = R our total charge is
total charge = 4π*ρ0(R³/3 + R³/4) = 4π*ρ0*R³/12 = π*ρ0*R³ / 3
and after substituting ρ0 = 3Q / πR³ we have
total charge = Q ◄
B) E = kQ/d²
since the distribution is symmetric spherically
C) dE = k*dq/r² = k*4π*ρ0(r² - r³/R)dr / r² = k*4π*ρ0(1 -
r/R)dr
so
E(r) = k*4π*ρ0*(r - r²/(2R)) from zero to r is
and after substituting for ρ0 is
E(r) = k*4π*3Q(r - r²/(2R)) / πR³ = 12kQ(r/R³ - r²/(2R^4))
which could be expressed other ways.
D) dE/dr = 0 = 12kQ(1/R³ - r/R^4) means that
r = R for a min/max (and we know it's a max since r = 0 is a
min).
<span>E) E = 12kQ(R/R³ - R²/(2R^4)) = 12kQ / 2R² = 6kQ / R² </span></span>
Answer:
3.46 A
Explanation:
The force (F) exerted on a wire of a particular length (L) carrying current (I) through a magnetic field (B) at an angle (θ) to the magnetic field is given as
F = (B)(I)(L) sin θ
F = 3.13 N
B = 0.360 T
I = ?
L = 2.50 m
θ = 79°
3.13 = (0.360 × I × 2.5 × sin 79°)
0.8835 I = 3.13
I = 3.54 A
But this is the resultant current in this magnetic field.
Since the two wires are conducting current in opposite directions,
Resultant current = 7 - (current in the other wire)
Current in the other wire = 7 - 3.54 = 3.46 A
Answer:
the Earth's crust is broken into about 12 plates that float on hotter, softer rocks in the underlying mantle
Explanation:
the different kids of food and the amount you should eat of them.
green:veggies
red:fruits
orange:grains
purple:protein
blue:dairy
Firm belief in the reliability, truth, ability, or strength of someone or something.
