Force Calculator (F = m·a)

Newton's second law: enter mass and acceleration, get force in newtons. Step-by-step working and pound-force conversion shown.

Inputs

In kilograms (kg).

In metres per second squared. Earth gravity ≈ 9.81 m/s².

Result

Force
98.100 N
  • In pound-force22.054 lbf
  • In dynes (CGS)9,810,000 dyn

Step-by-step

  1. Apply Newton's second law: F = m × a.
  2. Substitute: F = 10 kg × 9.81 m/s² = 98.100 N.
  3. Convert to pound-force: 98.100 N × 0.2248 = 22.054 lbf.

How to use this calculator

  • Enter the mass of the object in kilograms.
  • Enter the acceleration in m/s². Use 9.81 for objects in free fall near Earth.
  • Read force in newtons, plus pound-force and CGS unit conversions.

About this calculator

Newton's second law states that the force on an object equals its mass times its acceleration. F = m·a is the foundation of classical mechanics: pushing a 10 kg box at 2 m/s² requires 20 N; lifting a 1 kg book against gravity requires 9.81 N. The unit of force, the newton, is defined exactly as the force needed to accelerate 1 kg at 1 m/s². For everyday intuition: 1 N is roughly the weight of a small apple. This calculator returns force in newtons, pound-force (engineering use), and dynes (CGS / particle physics).

Frequently asked

1 newton is roughly the weight of a small apple (~100 g) under Earth gravity. It is the force needed to accelerate 1 kg at 1 m/s².

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