When dealing with force in physics or engineering, it’s important to understand the different units used across various measurement systems. Two commonly used units are the Newton (N) and the Poundal (pdl). These units come from different systems: Newton is from the SI (International System of Units), while Poundal is part of the Imperial or English Engineering System.
Whether you’re a student, engineer, or simply curious about unit conversions, this guide will walk you through the difference between Newtons and Poundals, why they matter, and how to convert between them easily and accurately.
What Is a Newton (N)?
The Newton is the SI (metric) unit of force. It’s named after Sir Isaac Newton, who developed the laws of motion.
Definition:
1 Newton is the force required to accelerate a 1-kilogram mass by 1 meter per second squared.
Formula: 1 N=1 kg⋅m/s21\, \text{N} = 1\, \text{kg} \cdot \text{m/s}^21N=1kg⋅m/s2
What Is a Poundal (pdl)?
The Poundal, although less commonly used today, is a unit of force in the foot–pound–second (FPS) system, specifically the absolute English system.
Definition:
1 Poundal is the force needed to accelerate a 1-pound mass by 1 foot per second squared.
Formula: 1 pdl=1 lb⋅ft/s21\, \text{pdl} = 1\, \text{lb} \cdot \text{ft/s}^21pdl=1lb⋅ft/s2
Newton vs Poundal: Key Differences
| Feature | Newton (N) | Poundal (pdl) |
|---|---|---|
| Measurement System | SI (Metric) | English Engineering (FPS) |
| Based On | Kilogram, meter, second | Pound, foot, second |
| Common Usage | Worldwide | Mostly U.S. (historically) |
| Conversion Factor | 1 N = 7.23301 pdl | 1 pdl = 0.138255 N |
| Application Areas | Science, engineering, physics | Historical, niche engineering uses |
Conversion Process: Newton to Poundal
To convert from Newtons to Poundals, multiply the force in Newtons by 7.23301.
Formula:
Poundals=Newtons×7.23301\text{Poundals} = \text{Newtons} \times 7.23301Poundals=Newtons×7.23301
Example:
Convert 10 N to poundals: 10 N×7.23301=72.3301 pdl10\, \text{N} \times 7.23301 = 72.3301\, \text{pdl}10N×7.23301=72.3301pdl
Conversion Process: Poundal to Newton
To convert from Poundals to Newtons, multiply the force in poundals by 0.138255.
Formula:
Newtons=Poundals×0.138255\text{Newtons} = \text{Poundals} \times 0.138255Newtons=Poundals×0.138255
Example:
Convert 50 pdl to Newtons: 50 pdl×0.138255=6.91275 N50\, \text{pdl} \times 0.138255 = 6.91275\, \text{N}50pdl×0.138255=6.91275N
Easy Conversion Chart: Newtons and Poundals
| Newtons (N) | Poundals (pdl) |
|---|---|
| 1 | 7.23301 |
| 5 | 36.16505 |
| 10 | 72.3301 |
| 20 | 144.6602 |
| 50 | 361.6505 |
| Poundals (pdl) | Newtons (N) |
|---|---|
| 1 | 0.138255 |
| 5 | 0.691275 |
| 10 | 1.38255 |
| 20 | 2.7651 |
| 50 | 6.91275 |
Why Is This Conversion Important?
Understanding the conversion between Newtons and Poundals is crucial for:
- Engineering Projects involving mixed-unit systems
- Physics problems where source data might use older Imperial units
- Technical documentation or historical reference materials
- Academic research comparing legacy and modern measurement systems
Tips for Converting Easily
- Use a Calculator or Converter Tool: If you’re dealing with a lot of conversions, use an online calculator or a mobile app to save time.
- Memorize Key Conversion Factors: Just remembering that 1 N ≈ 7.23 pdl and 1 pdl ≈ 0.138 N can go a long way.
- Check Your Units: Always make sure your mass is in kilograms when using Newtons, and pounds for poundals.
- Label Your Results: Clearly mark your answers with the appropriate unit to avoid confusion.
Frequently Asked Questions (FAQs)
1. Is the poundal still used today?
Not widely. The poundal is mostly of historical interest or found in legacy systems. Most modern physics and engineering work use the Newton.
2. Can I convert directly between Newtons and pounds-force?
Yes, but pounds-force (lbf) is a different unit than poundal. 1 lbf=4.44822 N1\, \text{lbf} = 4.44822\, \text{N}1lbf=4.44822N
So you’ll need a different conversion if dealing with lbf.
3. Are Newtons more accurate than poundals?
Not necessarily more accurate, but Newtons are part of the SI system, which is the globally accepted standard for scientific measurement.
Conclusion: Newton vs Poundal – Know the Difference, Convert with Confidence
Whether you’re crunching numbers for an engineering project, working on physics homework, or just exploring how different measurement systems work, knowing how to convert between Newtons and Poundals is a useful skill.
Remember:
- 1 N = 7.23301 pdl
- 1 pdl = 0.138255 N
With a solid understanding of the conversion process, you can work effortlessly across both systems. Bookmark this guide or share it with anyone who might benefit from a quick, reliable reference.