Resistance = V / I
= 12 / 3 = 4
Answer:
Because the force is inversely proportional to the square of the distance
Explanation:
The magnitude of the electrostatic force between two charged particles is given by

where
k is the Coulomb's constant
q1, q2 are the magnitudes of the two charges
d is the distance between the two charges
We observe that the magnitude of the force is inversely proportional to the square of the distance.
Therefore, when the distance changes to

The force will double:

Forces are vectors. They cancel each other when in opposite directions. Use the equation F=GMm/r^2 and find the difference between the two forces since they are directly opposing each other.
To solve this exercise it is necessary to take into account the concepts related to Pressure depending on the Force and the Area.
The pressure is defined as

Where,


Our values are given as,


Where
is the mass of the person and
is mass of cycle. Therefore the total mass at the system is 105Kg.
For Newton's second law we have:
where a is the acceleration, in this case the same Gravitational acceleration.
We need to make two considerations, the first is to calculate the total weight and second to calculate the weight on each wheel (2), that is


Force in each wheel,


In this way we can now calculate the length based on the pressure, that is





Therefore each tire has 3.21cm