122k views
2 votes
Use exercise 23 to find a general formula for the length of a helix of radius r and height h. What is the question?

a) Derive the parametric equations for the helix.
b) Calculate the curvature of the helix.
c) Determine the helix's pitch and frequency.
d) Find the length of the helix using the provided exercise.

User Daprezjer
by
8.0k points

1 Answer

5 votes

Final answer:

To find the length of a helix, one can use the parametric equations of the helix in conjunction with integration.

Step-by-step explanation:

The student is asking for a general formula to find the length of a helix with radius r and height h. It is important to note that in mathematics, the length of a curve can be found via integration if its parametric equations are known. Assuming that exercise 23 has provided us with the necessary background or a related formula, our task is to apply this knowledge to derive the required formula.

A helix can be described parametrically as x(r, t) = r cos(t), y(r, t) = r sin(t), z(h, t) = (h/2\u03c0)t, where t is the parameter that varies (typically the angle), r is the radius, and h is the height the helix gains every full revolution. The length L of one revolution of the helix is then:

L = \u222b \u221a{ (dx/dt)^2 + (dy/dt)^2 + (dz/dt)^2 } dt

This integral calculates the length of one full turn of the helix as t goes from 0 to 2\u03c0. Given that the student has height h for a specific section of the helix, we can calculate the number of turns n as h/\u03c0r. The total length L of the helix is given by multiple revolutions, therefore:

L_total = n * L = * \u222b \u221a{ (dx/dt)^2 + (dy/dt)^2 + (dz/dt)^2 } dt

In this formula, we insert the parametric derivatives and integrate to find the general length for any given r and h.

User Abhishek Galoda
by
8.8k points