What is the Equation for Finding Vector Magnitude in 2D and 3D?

In summary, the problem states that Vx = 18 m/s and Vy = 45 m/s and the asker is looking for help with finding the magnitude of the vector. It is not specified if the movement takes place in 2 or 3 dimensions, but it is assumed that vz = 0. The formula for finding the magnitude of a vector when all its components are known is discussed and it is noted that the same answer is obtained whether using the 2D or 3D equation.
  • #1
needsphysics
1
0

Homework Statement



Vx = 18 m/s and Vy = 45 m/s

Homework Equations



This is what I am not understanding, could anyone help with the equation process to finding the magnitude?

Thank you!
 
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  • #2
Do we know if the movement takes place in 2 or in 3 dimensions?
 
  • #3
cwasdqwe said:
Do we know if the movement takes place in 2 or in 3 dimensions?

It does not matter.

To the OP: what is the formula for the magnitude of a vector if we know all its components? You must have seen this somewhere...
 
  • #4
nrqed said:
...what is the formula for the magnitude of a vector if we know all its components? You must have seen this somewhere...

To define all its components you must know the dimension... but okay, let's assume [itex]v_{z}=0[/itex]...
 
  • #5
cwasdqwe said:
To define all its components you must know the dimension... but okay, let's assume [itex]v_{z}=0[/itex]...

Yes, I assume that [itex] v_z =0 [/itex] since no value is provided. It would be strange if ## v_z ## was not zero and they would not give us the value. My point is that then we get the same answer whether we use the magnitude equation in 2D or in 3D.
 

FAQ: What is the Equation for Finding Vector Magnitude in 2D and 3D?

How is the magnitude of a vector calculated?

The magnitude of a vector is calculated using the Pythagorean theorem, where the square root of the sum of the squares of the vector's components is taken. In other words, the magnitude is equal to the square root of (x^2 + y^2 + z^2), where x, y, and z are the components of the vector in three-dimensional space.

What is the difference between magnitude and direction in a vector?

The magnitude of a vector represents its size or length, while the direction of a vector represents its orientation in space. In other words, the magnitude is the quantity of the vector, while the direction is the angle at which the vector is pointing.

Can the magnitude of a vector be negative?

No, the magnitude of a vector is always a positive number. It represents the distance or length of the vector, which cannot be negative. However, the components of a vector can be negative, which can affect the direction of the vector.

How is vector magnitude used in physics and engineering?

Vector magnitude is used in physics and engineering to represent physical quantities such as force, velocity, and acceleration. It is also used in calculating the magnitude of electric and magnetic fields, as well as in solving problems involving motion and forces in three-dimensional space.

Can the magnitude of a vector be greater than the sum of its components?

No, the magnitude of a vector cannot be greater than the sum of its components. The magnitude is calculated using the Pythagorean theorem, which takes into account the sum of the squares of the vector's components. Therefore, the magnitude can never exceed the sum of the components.

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