Why do people not use permanent magnets when making electric motors with large capacity to create magnetic fields?

What is the momentum of a 2 kg object moving at 15 meters per second

The coulomb's law explains which of the following? select all the force between two charged objects is inversely proportional to the charge on each object. the force between two charged objects is directly proportional to the charge on each object. the force between two charged objects is directly proportional to the distance separating them. the force between two charged objects is inversely proportional to the square of the distance separat coulomb's law is similar to newton's 2nd law. if the force between two objects is f and the charge on both objects is doubled, the new force between the would now be 2f. if the force between two objects is 2f and the distance separating them is doubled, the new force between the objects would now o the be zf.

Multiply or divide to make this english distance conversion. 174 inches = feet (14.5, 58, 2,088, 23)