"Isaac Newton was born on January 4, 1643, in Woolsthorpe, England, Isaac Newton was an established physicist and mathematician, and is credited as one of the great minds of the 17th century Scientific Revolution. With discoveries in optics, motion and mathematics, Newton developed the principles of modern physics" - Google
Newton's first law of motion states "a body remains at rest or in motion with a constant velocity unless acted upon by an external force" Isaac Newton."
Inertia is described as a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force such as gravity, wind resistance, etc.
To find the acceleration rearrange the equation F = ma, which can change using this formula and switching it around to solve for acceleration by dividing both sides by the mass, so a = F/m. To find the acceleration, simply divide the force by the mass of the object being accelerated.