Which of the following best describes gravitational force?
a- an attraction between two objects that have mass.
b- an attraction between two objects due to their electrons.
c- the force that keeps atoms and molecules bound together.
d-the force that keeps objects from moving when they are at rest
this is for science

What is work? how much work is done to move an object 0 meters?

How is coal extracted from mountaintop removal mines? a. dynamite is used to create underground tunnels where miners go to extract the coal. b. dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal. c. coal in mountaintops is extracted by digging strips in the landscape to reach the coal. d. placer deposits in mountain river bottoms are removed by

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e