Question

23: A drilling machine is to have 8 speeds ranging from 100 rev/min to 1000 rev/min. If the speeds form a geometric progression, determine individual speed correct to the nearest whole number by using MATLAB or an appropriate standard engineering software. Please take a screenshot of the solution.

Answer 1

Step 1: Set the initial known values of speed and the amount of speeds “n”:

Step 2: Calculate the factor m of the geometric progression using the equation: . Note that s8 is the maximum speed and S1 the minimum speed.

Step 3: Write the expression to obtain all speeds of the machine rounded to the closest whole number.

The code used is:

S1=100
S8=1000
n=8
m= (S8/S1).^(1/(n-1))
S = round(S1*m.^(0:n-1))

And the results when runing said code are:

Si = 100 | 58 = 1000 n = 8 m = 1.3895 Ss 100 139 193 268 373 518 720 1000

Where S are the eight speeds of the machine