When the positive and negative charges grow large enough, a giant spark, lightning, occurs between the two charges within the cloud.
Answer: The coefficient of kinetic friction is μ = 0.6
Explanation:
For an object of mass M, the weight is:
W = M*g
where g is the gravitational acceleration: g = 9.8m/s^2
And the friction force between this object and the surface can be written as:
F = W*μ
where μ is the coefficient of friction (kinetic if the object is moving, and static if the object is not moving, usually the static coefficient is larger)
In this case, the weight is:
W = 20N
And the friction force is:
F = 12N
Replacing these values in the equation for the friction force we get:
12N = 20N*μ
(12N/20N) = μ = 0.6
The coefficient of kinetic friction is μ = 0.6
This is the half life of the substance. The half life is the time it takes for the substance to become reduced by half as a consequence of decay.
Answer:
Ohm's Law
Explanation:
The relationship: 
where V represents the voltage across a resistor of resistance "R" through which a current (I) flows,
is known as Ohm's Law in honor of Georg Ohm, who discover this proportionality.
