Explore More Physics Tools
Mastering the Forces of Physics
Sir Isaac Newton changed the way we see the world with a simple equation: F = ma. Whether you are an engineer converting thrust units, a student solving physics problems, or just curious how much you'd weigh on Jupiter, our Force Converter is the ultimate tool for understanding the forces around (and above) us.
Advanced Tool Features
F=ma Calculator
Switch to the "F=ma" tab to solve for Force, Mass, or Acceleration instantly. Perfect for homework checks.
Space Weight
Use the "Planetary Weight" mode to see your weight on the Moon (16% gravity) vs Jupiter (250% gravity).
Real Physics Units
Convert complex units like Dynes, Poundals, and Kilonewtons with scientific precision.
Understanding Force
- Newtons (N): The standard unit. Push a 1kg box to make it speed up by 1 m/s every second? You used 1 Newton.
- Balanced Forces: If you push a wall and it doesn't move, forces are balanced. The wall pushes back equally (Normal Force).
- Unbalanced Forces: These cause acceleration. If you push harder than friction resists, the object moves.
Common Mistakes
- Mass ≠ Weight.
In everyday language we mix them up, but in physics, Mass is constant (kg), Weight is a force (N) that depends on gravity.
- Pounds (lb) vs Pound-force (lbf).
"lb" usually means mass. "lbf" means force. 1 lbf is the force of gravity on 1 lb of mass.
Did You Know?
- The "Apple" Myth.
It's said an apple fell on Newton's head. While likely exaggerated, an apple weighs about 1 Newton (100g), making it a perfect example.
- Strongest Force?
Gravity is actually the *weakest* of the four fundamental forces. The Strong Nuclear Force is 10^38 times stronger!
Frequently Asked Questions
What is the difference between Mass and Weight?
Mass is the amount of matter in an object (kg). It never changes. Weight is the force of gravity acting on that mass (N). weight changes depending on where you are (Earth vs. Moon).
How do I convert kg to Newtons?
On Earth, multiply mass (kg) by 9.81. So, 1 kg weighs approximately 9.81 Newtons.
What is 1 Newton equal to?
1 Newton is roughly the weight of a small apple (approx 100g). It is the force needed to accelerate 1 kg by 1 m/s².
How much is 1 Pound-force (lbf) in Newtons?
1 lbf is approximately 4.448 Newtons. This is why rocket thrust in the US is often measured in pounds, while science uses Newtons.
Why do use 'kgf' (Kilogram-force)?
kgf is intuitive because 1 kgf is exactly the weight of 1 kg mass on Earth. However, it is not a standard SI unit and can be confusing in physics calculations.
What is a Dyne?
A Dyne is a tiny unit of force used in the centimeter-gram-second (CGS) system. It is equal to 0.00001 Newtons.
How much would I weigh on the Moon?
You would weigh about 1/6th (16.5%) of your Earth weight. If you weigh 150 lbs on Earth, you'd weigh only 25 lbs on the Moon.
What is 'g-force' in terms of Force?
G-force is a multiplier of your weight. At 2g, you feel a force equal to twice your normal body weight pressing on you.
Can Force exist without motion?
Yes. This is called Static Force (e.g., pushing against a wall). Work is only done if the object moves, but force is still applied.
What is Thrust?
Thrust is the reaction force described by Newton's 3rd Law (Action/Reaction). A rocket pushes gas out the back, and the gas pushes the rocket forward.