The SI unit of force is the newton (N). Named after Sir Isaac Newton, the newton is defined as the amount of force required to accelerate a one-kilogram mass by one meter per second squared. In terms of dimensions, one newton equals one kilogram meter per second squared (kg·m/s²). The newton is widely used in physics and engineering to measure force, weight, and other related concepts. Understanding force in newtons is essential for calculations in mechanics, as it helps quantify how objects interact under various conditions, including gravity, friction, and applied forces.