Let's start by visualising this concept.
Number of grains on square:
1 2 4 8 16 ...
We can see that it starts to form a geometric sequence, with the common ratio being 2.
For the first question, we simply want the fifteenth term, so we just use the nth term geometric form:
Thus, there are 16, 384 grains on the fifteenth square.
The second question begs the same process, only this time, it's a summation. Using our sum to n terms of geometric sequence, we get:
Thus, there are 32, 767 total grains on the first 15 squares, and you should be able to work the rest from here.
8.9
The equation for the grain size is expressed as the equality:
Nm(M/100)^2 = 2^(n-1)
where
Nm = number of grains per square inch at magnification M.
M = Magnification
n = ASTM grain size number
Let's solve for n, then substitute the known values and calculate.
Nm(M/100)^2 = 2^(n-1)
log(Nm(M/100)^2) = log(2^(n-1))
log(Nm) + 2*log(M/100) = (n-1) * log(2)
(log(Nm) + 2*log(M/100))/log(2) = n-1
(log(Nm) + 2*log(M/100))/log(2) + 1 = n
(log(33) + 2*log(270/100))/log(2) + 1 = n
(1.51851394 + 2*0.431363764)/0.301029996 + 1 = n
(1.51851394 + 0.862727528)/0.301029996 + 1 = n
2.381241468/0.301029996 + 1 = n
7.910312934 + 1 = n
8.910312934 = n
So the ASTM grain size number is 8.9
If you want to calculate the number of grains per square inch, you'd use the
same formula with M equal to 1. So:
Nm(M/100)^2 = 2^(n-1)
Nm(1/100)^2 = 2^(8.9-1)
Nm(1/10000) = 2^7.9
Nm(1/10000) = 238.8564458
Nm = 2388564.458
Or about 2,400,000 grains per square inch.
Hi,
The volume of the cylinder is :
V = π × r^2 × h
V = 3,142 × (2)^2 × 5
V = 62, 8319 cm^3
π : Pi => 3,142
r : radius of the cylinder (2 units).
h : height of the cylinder (5 units).
The base of the cylinder is a circle , so to calculate the area we have to use the formula : area = π × r^2. And to find the volume , we have to multiply the area by the height.
•It was nice to help you, Bellalocc!
<span>3x - 2y + 2y > -14 + 2y </span>
<span>3x + 0 > -14 + 2y </span>
<span>3x > -14 + 2y </span>
<span>3x + 14 > -14 + 14 + 2y </span>
<span>3x + 14 > 0 + 2y </span>
<span>3x + 14 > 2y </span>
<span>(3x + 14)/2 > 2y/2 </span>
<span>(3x + 14)/2 > y*(2/2) </span>
<span>(3x + 14)/2 > y*(1) </span>
<span>(3x + 14)/2 > y </span>
<span>y < (3x + 14)/2 </span>
<span>y < 3x/2 + 14/2 </span>
<span>y < 3x/2 + 7 </span>
<span>y < (3/2)*x + 7 </span>
<span>“y” is LESS THAN (3/2)*x + 7 </span>
<span>the slope intercept form of the inequality is: y < (3/2)*x + 7 </span>
<span>STEP 2: Temporarily change the inequality into an equation by replacing the < symbol with an = symbol. </span>
<span>y < (3/2)*x + 7 </span>
<span>y = (3/2)*x + 7 </span>
<span>STEP 3: Prepare the x-y table using the equation from Step 2. </span>
<span>Using the slope intercept form of the equation from Step 2, choose a value for x, and then compute y for at least three points. </span>
<span>Although you could plot the graph with just two sets of x-y coordinates, you should compute at least three different sets of coordinates points to ensure you have not made a mistake. All three x-y coordinates must lie on the same straight line. If they do not, you have made a mistake. </span>
<span>You can choose any value for x. </span>
<span>For example, (arbitrarily) choose x = -2 </span>
<span>If x = -2, </span>
<span>y = (3/2)*x + 7 </span>
<span>y = (3/2)*(-2) + 7 </span>
<span>y = 4 </span>
4z ≥ 7
divide seven by four
z ≥ 1.75
or, if you need it in fraction form, it would be
z ≥ 7/4
