Newton's second law

An object accelerates when there is a resultant force on it. The resultant force is the combined effect of all the forces acting on the object. Its acceleration is in the same direction as the resultant force.

Newton’s second law relates the resultant force to the object’s mass and acceleration:

Here, $$F$$ is the resultant force in newtons ($$\mathrm{N}$$), $$m$$ is the mass in kilograms ($$\mathrm{kg}$$), and $$a$$ is the acceleration in metres per second squared ($$\mathrm{m/s^2}$$).

For a given mass, a larger resultant force produces a larger acceleration. For a given resultant force, a larger mass produces a smaller acceleration: more force is needed to give a more massive object the same acceleration.