Answer:
a) V = -0.227 mV
b) V = -0.5169 mV
Explanation:
a)
Inside a sphere with a uniformly distributed charge density, electric field is radial and has a magnitude
E = (qr) / (4πε₀R³)
As we know that
V = -
By solving above equation, we get
V = (-qr²) / (8πε₀R³)
When
R = 1.81 cm
r = 1.2 cm
q = +2.80 fC
ε₀ = 8.85 × 10⁻¹²
V = (-2.80 × 10⁻¹⁵ × (1.2 × 10⁻²)²) / (8 × 3.14 × 8.85 × 10⁻¹² × (1.81 × 10⁻²)³)
V = -2.27 × 10⁻⁴ V
V = -0.227 mV
b)
When
r = R
R = 1.81 cm
q = +2.80 fC
ε₀ = 8.85 × 10⁻¹²
V = (-qR²) / (8πε₀R³)
V = (-q) / (8πε₀R)
V = (-2.80 × 10⁻¹⁵) / (8 × 3.14 × 8.85 × 10⁻¹² × (1.81 × 10⁻²))
V = -5.169 × 10⁻⁴ V
V = -0.5169 mV
(a) 
First of all, we need to calculate the acceleration of the person, by using the following SUVAT equation:
where
v = 0 is the final velocity
u = 20.0 m/s is the initial velocity
a is the acceleration
d = 1.00 cm = 0.01 m is the displacement of the person
Solving for a,
And the average force on the person is given by
with m = 75.0 kg being the mass of the person. Substituting,
where the negative sign means the force is opposite to the direction of motion of the person.
b) 
In this case,
v = 0 is the final velocity
u = 20.0 m/s is the initial velocity
a is the acceleration
d = 15.00 cm = 0.15 m is the displacement of the person with the air bag
So the acceleration is
So the average force on the person is
Answer:
Melting point
Explanation:
when a solid turns to a liquid, it is melting
Answer:
|F| = 2.09 × 10⁻⁸ assuming that the two ions are point charges.
Explanation:
What's the charge on each ion?
The symbol 
here stands for fundamental charge. Each electron carries a negative fundamental charge of -e. Each proton carry a positive fundamental charge of +e.
Molecules and atoms are neutral. They contain an equal number of electrons and protons. Remove one electron from a molecule or atom, and that particle will end up with more protons (which are positive) than electrons. That particle will carry a positive charge of +e become an ion (a cation to be precise.) Remove another electron and the ion will carry a charge of +2e.
For each ion 
.
What's the size of the electrostatic force between the two ions?
Consider Coulomb's Law for the electrostatic force 
between two point charges:
,
where
is Coulomb's constant,
and 
are the charge on the two point charges, and
is the separation between the two charges.
Make sure that all values are in SI units. Assume that the two ions are small enough that they act like point charges:
.
The value of is negative, meaning that the two charges will repel each other because they are both positive. The question is asking for the magnitude of this force. Thus drop the sign in front of to obtain 
, which is the magnitude of .
Answer:
the branch of mechanics concerned with the interaction of electric currents with magnetic fields or with other electric currents.
Explanation:
