The second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

This can be expressed mathematically as:

F = m * a

Where:

* F is the net force acting on the object (in Newtons)

* m is the mass of the object (in kilograms)

* a is the acceleration of the object (in meters per second squared)

To find the mass equation from this, we can rearrange the equation to solve for m:

m = F / a

This equation tells us that the mass of an object is equal to the net force acting on it divided by its acceleration.