Gravitational force: two small objects, with masses m and m, are originally a distance r apart, and the magnitude of the gravitational force on each one is f. the masses are changed to 2m and 2m, and the distance is changed to 4r. what is the magnitude of the new gravitational force?

Law of universal gravitation:

F = GMm/r²

F = gravitational force, G = gravitational constant, M & m = masses of the objects, r = distance between the objects

F is proportional to both M and m:

F ∝ M, F ∝ m

F is proportional to the inverse square of r:

F ∝ 1/r²

Calculate the scaling factor of F due to the change in M:

k₁ = 2M/M = 2

Calculate the scaling factor of F due to the change in m:

k₂ = 2m/m = 2

Calculate the scaling factor of F due to the change in r:

k₃ = 1/(4r/r)² = 1/16

Multiply the original force F by the scaling factors to obtain the new force:

Fk₁k₂k₃

= F(2)(2)(1/16)

= F/4

Hello There

Answers: 

1) BEVs and hydrogen fuel cell vehicles are more promising for the future because they reduce gas emissions as well as CO2 which makes our planet less-pulluted

2) This is an opinion. Mine is that they should be required to at least have it be an option to buy.

I hope this helps
-Chris