Calc Help: Moving Particle from Origin & Integral of 5^ radical x

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Discussion Overview

The discussion revolves around two main topics: calculating the work needed to move a particle under a force towards the origin and finding the integral of the function \(5^{\sqrt{x}}\). The scope includes mathematical reasoning and technical explanations related to calculus.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant asks how much work is needed to move a particle from one position to another under a force pulling it towards the origin, but the phrasing of the question is questioned by another participant.
  • Another participant suggests defining the distance from the origin as \(d\) and the force as \(F\), but expresses confusion about the specific positions referenced.
  • A participant proposes a substitution method for integrating \(5^{\sqrt{x}}\) and suggests looking up integral tables for potential solutions.
  • Another participant provides a specific integral result for \(\int 5^{x^{\frac{1}{n}}}dx\) from an external source, indicating a complex expression involving the Gamma function.
  • A later reply reiterates the integral result, expressing satisfaction with the progress made.
  • One participant posits that the constant force towards the origin suggests a vector field, implying that the work done can be calculated using a line integral over the path between two points.
  • Another participant echoes the idea of using a line integral to calculate work in the context of the vector field described.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and approaches to both the work calculation and the integral, with no consensus reached on the best method or solution for either problem.

Contextual Notes

The discussion includes unresolved assumptions about the definitions of positions and forces, as well as the complexity of the integral, which may depend on the specific values of \(n\).

parwana
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When particle is at distance meters from the origin, there is a force of Newtons (N) pulling it toward the origin. How much work is needed to move the particle from the position to the position ?



and




What is integral of 5^ radical x ?
 
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That's a very strangely worded question. Let's call the distance from the origin, d, the force, F. Now what on Earth do you mean "from the position to the position?" What position to what position? Very strange?!...

[tex]\int 5^{\root n\of x}dx[/tex]

Let [itex]u = x^{1/n}[/itex], therefore [itex]du = \frac{1}{n}x^{1/n - 1}dx[/itex].

[tex]dx = \frac{ndu}{x^{1/n - 1}}[/tex]

[tex]n\int \frac{5^udu}{u^{1 - n}}[/tex]

Hmmm... maybe this is a start, I don't know where to go with this.

EDIT: Look up integral tables, see if they have ways to solve things like [itex]\int u5^udu[/itex], you might be able to solve this for the first few n (n = 1, 2, 3), and if you find a pattern, you might be able to use induction to prove it generally.
 
Last edited:
Your integral is way beyond me. But http://integrals.wolfram.com/index.en.cgi says:

[tex]\int 5^{x^{\frac{1}{n}}}dx = -nx \left(-x^{\frac{1}{n}} \right)^{-n} \Gamma \left( n, -x^{\frac{1}{n}} \ln 5 \right) \left(\ln 5\right)^{-n} + C[/tex]
 
Zurtex said:
[tex]\int 5^{x^{\frac{1}{n}}}dx = -nx \left(-x^{\frac{1}{n}} \right)^{-n} \Gamma \left( n, -x^{\frac{1}{n}} \ln 5 \right) \left(\ln 5\right)^{-n} + C[/tex]
Hah! Yes, I knew I was close :wink:.
 
Wouldn't the constant force towards the origin indicate a vector field of constant magnitude with all vectors pointing toward the origin? So the work from any two positions would just be the line integral for the straight line between any two points over this vector field.
 
Last edited:
µ³ said:
Wouldn't the constant force towards the origin indicate a vector field of constant magnitude with all vectors pointing toward the origin? So the work from any two positions would just be the line integral for the straight line between any two points over this vector field.

The line integral of the component of force parallel to the straight line over the line segment.
 

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