The law of motion that states that an object's acceleration is directly related to the net force applied and inversely related to the mass of the object is

Newtons 2nd law

F = ma

Explanation:

Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

b.a device that inputs heat into a cool object

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.