Force Calculator
Inputs
Enter parameters to calculate Force, Mass, or Acceleration.
Understanding Force
Force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate.
Force is a vector quantity, meaning it has both magnitude and direction. It is measured in the SI unit of Newtons (N).
Newton's Second Law
This calculator is based on Isaac Newton's Second Law of Motion, which states that the force acting on an object is equal to the mass of that object multiplied by its acceleration.
F = m × a- F = Net Force (Newtons, N)
- m = Mass (Kilograms, kg)
- a = Acceleration (meters per second squared, m/s²)
The Unit: Newton (N)
One Newton is defined as the force needed to accelerate one kilogram of mass at the rate of one meter per second squared.
1 N = 1 kg·m/s²
Examples
Example 1: Pushing a Car
You push a 1,000 kg car with enough strength to accelerate it at 0.05 m/s².
- Mass (m) = 1,000 kg
- Acceleration (a) = 0.05 m/s²
- Force (F) = 1000 × 0.05 = 50 N
Example 2: Gravity
What is the force of gravity on a 70 kg person?
- Mass (m) = 70 kg
- Acceleration (a) = 9.8 m/s² (Earth's gravity)
- Force (F) = 70 × 9.8 = 686 N (This is their weight!)
Frequently Asked Questions
Is mass different from weight?
Yes! Mass is the amount of matter in an object (measured in kg) and doesn't change. Weight is the force of gravity acting on that mass (measured in N).
What if acceleration is zero?
If acceleration is zero (constant velocity), the net force acting on the object is zero. This is Newton's First Law (Inertia).
Can I use pounds for mass?
In physics equations like F=ma, it's safer to convert pounds (lbs) to kilograms (kg) first. 1 kg ≈ 2.20462 lbs.