Calculadora da Segunda Lei de Newton
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
F = m·a
About this calculator
The Newton's Second Law Calculator solves the fundamental equation of dynamics: F = m·a. It allows you to calculate the net force, mass, or acceleration of a body, as long as the other two values are known. This tool is useful for physics students, engineers, and professionals who need to quickly verify relationships between these quantities.
The operation is simple: enter two of the three parameters (force in newtons, mass in kilograms, acceleration in m/s²) and the calculator applies the formula to obtain the third. For example, if you know the mass of a car and the acceleration it achieves, you can determine the net force from the engine. Accuracy depends on the values entered.
Use this calculator in everyday situations: calculate the force needed to accelerate an object, determine the acceleration of a body under a known force, or find the mass of an object from force and acceleration measurements. It is especially useful in engineering projects, laboratory experiments, and physics problem-solving.
Important precautions: ensure you use consistent SI units. The formula is only valid for systems where mass is constant and there are no significant dissipative forces. In situations with friction or air resistance, the actual net force may differ from the calculated one, as the formula considers the total net force.
Frequently asked questions
Can I use this calculator for objects with variable mass, like a rocket burning fuel?
No, the formula F = m·a assumes constant mass. For variable mass, use Tsiolkovsky's rocket equation.
What is the difference between net force and applied force?
Net force is the vector sum of all forces acting. Applied force is just one of them. The calculator uses net force.
Can I use units other than newton, kilogram, and m/s²?
The calculator expects SI units. If using others, convert first to avoid errors.
Does the calculator consider the direction of force?
No, it only calculates magnitude. For direction, you need separate vector analysis.
What happens if I enter zero for mass?
Division by zero is undefined. Mass must be greater than zero for acceleration or force calculations.