Does the nabla operator has a unit?

In summary, the nabla operator is typically used in physics and has a unit of 1/length, with specific units depending on the space it is being used in. However, there may be cases where the nabla operator does not have this unit, such as in momentum space.
  • #1
jwillie2000
2
0
Hello Everyone,

I have a small question bothering me. I wan to know whether the nabla operator has a unit? I am thinking it does and it should be 1/m. I just want to make sure whether this is true. Thanks!

Jimmy
 
Physics news on Phys.org
  • #2
Mathematics operators in general don't have units. If, of course, you are applying them to specific physical quantities, the quantities carry their units with them. For example, if y is in meters and x is in seconds, then dy/dt would have units of "meters per second".

If f(x,y,z) gives the temperature, in degrees Celcius, at point (x, y, z) where the coordinates are measured in meters from some fixed origin, then
[tex]\nabla f= \frac{\partial f}{\partial x}\vec{i}+ \frac{\partial f}{\partial y}\vec{j}+ \frac{\partial f}{\partial z}\vec{k}[/tex]
is a vector with each component in "degrees per meter". Or if f(x,y,z) is pressure in pounds per square foot and x, y, and z are in feet, then each component of [itex]\nabla f[/itex] is in "pounds per cubic foot". (Though it would probably be better to think "pounds per square foot per foot".)
 
  • #3
jwillie2000 said:
Hello Everyone,

I have a small question bothering me. I wan to know whether the nabla operator has a unit? I am thinking it does and it should be 1/m. I just want to make sure whether this is true. Thanks!

Jimmy

HallsOfIvy is right. In physics, the nabla operator has units of 1/Length.
 
  • #4
Hi HallsOfIvy,

And thanks for replying to my post. If i got you well, it is better to leave it without unit when say defining it in the nomenclature of a thesis? In my thesis, length was measured mostly in metres. So do i indicate 1/m as the unit of the nabla operator or just leave it without unit?

Jimmy
 
  • #5
Rap said:
HallsOfIvy is right. In physics, the nabla operator has units of 1/Length.

One caveat to this is the fact that you can define gradients that aren't the typical vector calculus gradients you are use to seeing. I honestly can't think of specific examples, but I know there are gradients that are NOT the [tex]{{\partial} \over {\partial x}} \hat x + {{\partial} \over {\partial y}} \hat y + {{\partial} \over {\partial z}} \hat z[/tex] typical kinda deal. If I'm not mistaken, you can define gradients for any space (not just the typical [tex]R^3[/tex] space). For example, if you want to work in some sort of momentum space, I suspect you could have gradients such as [tex]{{\partial} \over {\partial P_x}} \hat P_x + {{\partial} \over {\partial P_y}} \hat P_y + {{\partial} \over {\partial P_z}} \hat P_z[/tex] that do not have units 1/length.
 
  • #6
Pengwuino said:
One caveat to this is the fact that you can define gradients that aren't the typical vector calculus gradients you are use to seeing. I honestly can't think of specific examples, but I know there are gradients that are NOT the [tex]{{\partial} \over {\partial x}} \hat x + {{\partial} \over {\partial y}} \hat y + {{\partial} \over {\partial z}} \hat z[/tex] typical kinda deal. If I'm not mistaken, you can define gradients for any space (not just the typical [tex]R^3[/tex] space). For example, if you want to work in some sort of momentum space, I suspect you could have gradients such as [tex]{{\partial} \over {\partial P_x}} \hat P_x + {{\partial} \over {\partial P_y}} \hat P_y + {{\partial} \over {\partial P_z}} \hat P_z[/tex] that do not have units 1/length.

Yes, I agree. The units depend on the units of the space you are dealing with.
 
  • #7
Hi.
the nabla operator has a unit 1/m in MKSA.
Regards.
 

Related to Does the nabla operator has a unit?

1. Does the nabla operator have a unit of measurement?

No, the nabla operator does not have a unit of measurement. It is a mathematical symbol used in vector calculus to represent a vector differential operator.

2. Why is the nabla operator sometimes written as ∇?

The symbol ∇ is the Greek letter "nabla" and is used to represent the nabla operator in mathematics. It is a shorthand notation that is commonly used in vector calculus.

3. What is the purpose of the nabla operator?

The nabla operator is used to perform vector calculus operations, such as calculating the gradient, divergence, and curl of a vector field.

4. Can the nabla operator be applied to scalar fields?

Yes, the nabla operator can be applied to scalar fields. In this case, it represents the gradient of the scalar field, which is a vector field.

5. What is the difference between the nabla operator and the del operator?

The nabla operator (∇) and the del operator (∂) are both used in vector calculus, but they have different meanings. The nabla operator represents a vector differential operator, while the del operator represents a partial derivative with respect to a specific variable.

Similar threads

  • Classical Physics
Replies
6
Views
414
  • Quantum Physics
2
Replies
56
Views
3K
  • Classical Physics
Replies
1
Views
1K
Replies
2
Views
2K
Replies
10
Views
778
  • Classical Physics
Replies
21
Views
1K
  • Classical Physics
Replies
2
Views
2K
  • Linear and Abstract Algebra
2
Replies
41
Views
3K
Replies
24
Views
882
Replies
1
Views
720
Back
Top