He would travel 67 1/2 miles in an hour.
The <em>total</em> area of all six faces of the tunnel is 
square centimeters.
<h2>Procedure - Surface area of a tunnel for a toy train</h2>
The surface area of the solid (
) used to represent the tunnel for a toy train is the sum of its six faces (two <em>semicircular</em> sections, inner <em>semicircular</em> arc section, outer <em>semicircular</em> arc section, two rectangles).
<h3>Determination of the surface area of the tunnel based on information of the diagram</h3>
We calculate the surface area as following:
![A = 2\cdot \frac{\pi}{2} \cdot [(10\,cm)^{2}-(8\,cm)^{2}] + \pi\cdot (8\,cm)\cdot (30\,cm) + \pi\cdot (10\,cm)\cdot (30\,cm) + 2\cdot (2\,cm)\cdot (30\,cm)](https://tex.z-dn.net/?f=A%20%3D%202%5Ccdot%20%5Cfrac%7B%5Cpi%7D%7B2%7D%20%5Ccdot%20%5B%2810%5C%2Ccm%29%5E%7B2%7D-%288%5C%2Ccm%29%5E%7B2%7D%5D%20%2B%20%5Cpi%5Ccdot%20%288%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%20%5Cpi%5Ccdot%20%2810%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%202%5Ccdot%20%282%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29)
The <em>total</em> area of all six faces of the tunnel is square centimeters. 
To learn more on surface areas, we kindly invite to check this verified question: brainly.com/question/2835293
Since the focus is at (0, 2) and directrix is y = -2
point where both of these have the same x-value will be at (0, 2) for the focus and (0, -2) for the directrix.
The vertex will also have the same x-value so it will be (0, y).
y-value is half-way between the y-value of the focus, and the y-value of the directrix at x = 0.
Directrix y-value is -2 at x = 0 and for the focus it's 2 at x = 0.
Halfway between y = -2 and y = 2 is y = 0.
So the vertex of the parabola occurs at (0, 0).
So that's x^2 = 4ay = 4(2)y = 8y.
y = 1/8*x^2
hope it helps
Ok so, here goes:
simple interest: r- rate, A- amount in the end, t- time, P- principal
<span>r = (1/t)(A/P - 1)
</span>Putting in our numbers
r = (1/4)((21236/5309) - 1) = 0.75
r = 0.75
Converting r decimal to R a percentage
R = 0.75 * 100 = 75%/year
The interest rate required to get a total amount, principal plus interest, of $21,236.00 from simple interest on a principal of $5,309.00 over 4 years is 75% per year.
Answer:
d) 2/5
Step-by-step explanation:
4/10 = 2/5
0, 1/10, 2/10, 3/10, 4/10, 5/10, 6/10, 7/10, 8/10, 9/10, 1
Hope this helps!
