Which atmospheric layer prevents meteoroids from reaching earth’s surface
1 answer:
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Answer:
<em> B) The voltage on dry skin needs to be 200 times larger than the voltage on wet skin.</em>
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Explanation:
This is the complete question
A person will feel a shock when a current of greater than approximately 100μ A flows between his index finger and thumb. If the resistance of dry skin is 200 times larger than the resistance of wet skin, how do the maximum voltages without shock compare in each scenario?
A) The voltage on dry skin needs to be 200 times smaller than the voltage on wet skin.
B) The voltage on dry skin needs to be 200 times larger than the voltage on wet skin.
C) The voltage on dry skin is the same as the voltage on wet skin.
D) The voltage on dry skin needs to be 40,000 times larger than the voltage on wet skin.
Ohm's law states that electric current is proportional to voltage and inversely proportional to resistance.
the equation is written as
V = IR
Where V is the voltage
I is the current
R is the resistance
for this case, the current I is 100μ A = 100 x 10^16 A
resistance of wet skin = R
resistance of dry skin = 200R
for the wet skin, voltage will be
V = IR =
for dry skin, voltage will be
V = IR =
Comparing both voltages
÷
= 200
<em>this means that the voltage on the wet skin should be 200 times lesser than the voltage on the dry skin or the voltage on the dry skin should be 200 times more than the voltage on the wet skin.</em>
Answer:
<em>His angular velocity will increase.</em>
Explanation:
According to the conservation of rotational momentum, the initial angular momentum of a system must be equal to the final angular momentum of the system.
The angular momentum of a system = 'ω'
where
' is the initial rotational inertia
ω' is the initial angular velocity
the rotational inertia =
where m is the mass of the system
and r' is the initial radius of rotation
Note that the professor does not change his position about the axis of rotation, so we are working relative to the dumbbells.
we can see that with the mass of the dumbbells remaining constant, if we reduce the radius of rotation of the dumbbells to r, the rotational inertia will reduce to .
From
'ω' =
ω
since is now reduced, ω will be greater than ω'
therefore, the angular velocity increases.