Answer:
That is not true all objects fall at the same speed excepts things like feathers or paper.
Answer:
Gravity.The weak force.
Electromagnetism.The strong force.
The answer is no. If you are dealing with a conservative force and the object begins and ends at the same potential then the work is zero, regardless of the distance travelled. This can be shown using the work-energy theorem which states that the work done by a force is equal to the change in kinetic energy of the object.
W=KEf−KEi
An example of this would be a mass moving on a frictionless curved track under the force of gravity.
The work done by the force of gravity in moving the objects in both case A and B is the same (=0, since the object begins and ends with zero velocity) but the object travels a much greater distance in case B, even though the force is constant in both cases.
The force per unit of length between two wires carrying current is

where I1 and I2 are the currents in the two wires, while r is the distance between them.
We can see from the formula that the force is proportional to the product between I1 and I2:

so, if we double both I1 and I2, we get a factor 4:

so, the force between the wires will be 4 times the original value.