This law has to do with the mass of an object. The mass of an object is how much weight, or force it is exerting in a certain direction. There is an equation used to describe this law, it is F = ma. This equation stands for Force equals the mass of the object multiplied by the acceleration of the object. The heavier the object is the more force you will have to exert on the object to get it to move at the same acceleration as another object. This equation is best shows when you throw a tennis ball versus a basketball. These two items have different masses meaning the force needed to be exerted will be different to get the same acceleration, and the acceleration will be different if you exert the same amount of force on the objects. The equation can be manipulated to be written m = F/a or a = F/m. This equations are the same exact thing as the original just rearranged to solve for different components of the equation.