Magnitude vs. Size: Understanding the Difference

In summary, magnitude and size are two different ways of describing a vector. Magnitude refers to the strength or intensity of the vector, while size refers to its representation on paper. The size of a vector is not as important as its magnitude, which is typically measured in units such as Newtons. It is not common to use a specific scale, such as 4cm = 9N, to represent a vector in scientific and mathematical contexts.
  • #1
Bassel AbdulSabour
8
0
What's the difference between magnitude and size? I mean, how can I say that AB vector has a magnitude of 9 Newton, and its length is 4 cm.
 
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  • #2
I can see a reason for them to be different. Suppose one draws ##\vec{AB}## 4 cm long and that should represent 9 N, then you have a scale of ##{9 \over 4} ## N/cm. Then AB has a size of 4 cm and a magnitude of 9 N.
 
  • #3
Bassel AbdulSabour said:
What's the difference between magnitude and size? I mean, how can I say that AB vector has a magnitude of 9 Newton, and its length is 4 cm.
You are trying to distinguish between the magnitude of a vector and the size of its representation drawn on a piece of paper? In my lifetime I have never heard anyone refer to the "size" of a vector in such a manner. Scientists, engineers and mathematicians are normally concerned with the vector, not with its representation.
 
  • #4
jbriggs444 said:
You are trying to distinguish between the magnitude of a vector and the size of its representation drawn on a piece of paper? In my lifetime I have never heard anyone refer to the "size" of a vector in such a manner. Scientists, engineers and mathematicians are normally concerned with the vector, not with its representation.
I agree completely. The fact that the vector is drawn as one 4 cm. in length is immaterial -- its magnitude is 9 Nt.
 
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  • #5
4cm = 9N is a horrible scale. Why not 1cm = 2N?
 

1. What is the difference between magnitude and size?

Magnitude refers to the measurement of an object's strength or intensity, while size refers to the physical dimensions of an object.

2. How are magnitude and size related?

Magnitude and size are often correlated, but they are not the same thing. For example, a large object may not necessarily have a high magnitude, and a small object may have a high magnitude.

3. Can you give an example to illustrate the difference between magnitude and size?

One example is the difference between the magnitude and size of earthquakes. The magnitude of an earthquake is measured on the Richter scale, which is based on the strength of seismic waves. The size of an earthquake, on the other hand, is measured by its surface area or the amount of ground that is affected by the earthquake.

4. How is magnitude vs. size important in scientific research?

Understanding the difference between magnitude and size is crucial in many scientific fields, such as astronomy, geology, and physics. It allows scientists to accurately describe and measure various phenomena, such as the brightness of stars, the strength of earthquakes, and the size of particles.

5. Is one more important than the other in scientific research?

Both magnitude and size are important in scientific research and have their own unique uses. It ultimately depends on the specific research being conducted and the parameters being measured. For some studies, magnitude may be more important, while for others, size may be the key factor. It is essential to understand and differentiate between the two concepts to accurately interpret and communicate scientific findings.

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