Newton's second law links the resultant force on a body to its acceleration. The equation is force = mass × acceleration, or F = m × a. Force is measured in newtons (N), mass in kilograms (kg) and acceleration in metres per second squared (m/s2). The force in the equation is always the resultant force.
The equation shows two things. For the same mass, a larger resultant force gives a larger acceleration. For the same resultant force, a larger mass gives a smaller acceleration. One newton gives a mass of one kilogram an acceleration of 1 m/s2.
The equation can be rearranged to give acceleration = force divided by mass, or mass = force divided by acceleration. For example, a car of mass 1500 kg with a resultant force of 3000 N has an acceleration of 3000 divided by 1500, which is 2 m/s2.