The quantity that has units kg m2/sec2 is known as a

Energy

Explanation:

The unit is .

We can see the formula of kinetic energy is

Where is the mass and is the velocity of the object.

Which means its unit would be kg times square of meter per second, that is  . Which is often referred as Joule.

Also, when look at the formula of work done by an object.

Where is the force and is the distance traveled by the object due to force .

We an see that its unit is kg meter per second squared times meter. That is equivalent to . This is also a type of energy.

So, the unit is the unit of energy.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

it doesn't. it was imagined up in the middle ages.