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3 years ago

12

Ann travels from Town A to Town B in 3 hours. She then takes another hour to travel from Town B to Town C. The distance from Tow

n A and Town B is 100 miles. The distances between Town B and Town C is 40 miles. What is Ann's average speed for the whole journey? *

1 answer:

fiasKO [112]3 years ago

7 0

Answer:

35 miles per hour

Step-by-step explanation:

Ann travels a total of (100 +40) = 140 miles in (3 +1) = 4 hours. Her average speed is the ratio of these:

speed = distance/time

speed = (140 miles)/(4 hours) = 35 miles/hour

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H=hour
10h+7=32 would be the best equation. Hope this helps!

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3 years ago

A norman window is constructed by adjoining a semicircle to the top of an ordinary rectangular. Find the dimensions of a norman

Yanka [14]

Answer:

$W\approx 8.72$ and $L\approx 15.57$ .

Step-by-step explanation:

Please find the attachment.

We have been given that a norman window is constructed by adjoining a semicircle to the top of an ordinary rectangular. The total perimeter is 38 feet.

The perimeter of the window will be equal to three sides of rectangle plus half the perimeter of circle. We can represent our given information in an equation as:

$2L+W+\frac{1}{2}(2\pi r)=38$

We can see that diameter of semicircle is W. We know that diameter is twice the radius, so we will get:

$2L+W+\frac{1}{2}(2r\pi)=38$

$2L+W+\frac{\pi}{2}W=38$

Let us find area of window equation as:

$\text{Area}=W\cdot L+\frac{1}{2}(\pi r^2)$

$\text{Area}=W\cdot L+\frac{1}{2}(\pi (\frac{W}{2})^2)$

$\text{Area}=W\cdot L+\frac{\pi}{2}(\frac{W}{2})^2)$

$\text{Area}=W\cdot L+\frac{\pi}{2}(\frac{W^2}{4})$

$\text{Area}=W\cdot L+\frac{\pi}{8}W^2$

Now, we will solve for L is terms W from perimeter equation as:

$L=38-(W+\frac{\pi }{2}W)$

Substitute this value in area equation:

$A=W\cdot (38-W-\frac{\pi }{2}W)+\frac{\pi}{8}W^2$

Since we need the area of window to maximize, so we need to optimize area equation.

$A=W\cdot (38-W-\frac{\pi }{2}W)+\frac{\pi}{8}W^2$

$A=38W-W^2-\frac{\pi }{2}W^2+\frac{\pi}{8}W^2$

Let us find derivative of area equation as:

$A'=38-2W-\frac{2\pi }{2}W+\frac{2\pi}{8}W$

$A'=38-2W-\pi W+\frac{\pi}{4}W$

$A'=38-2W-\frac{4\pi W}{4}+\frac{\pi}{4}W$

$A'=38-2W-\frac{3\pi W}{4}$

To find maxima, we will equate first derivative equal to 0 as:

$38-2W-\frac{3\pi W}{4}=0$

$-2W-\frac{3\pi W}{4}=-38$

$\frac{-8W-3\pi W}{4}=-38$

$\frac{-8W-3\pi W}{4}*4=-38*4$

$-8W-3\pi W=-152$

$8W+3\pi W=152$

$W(8+3\pi)=152$

$W=\frac{152}{8+3\pi}$

$W=8.723210$

$W\approx 8.72$

Upon substituting $W=8.723210$ in equation $L=38-(W+\frac{\pi }{2}W)$ , we will get:

$L=38-(8.723210+\frac{\pi }{2}8.723210)$

$L=38-(8.723210+\frac{8.723210\pi }{2})$

$L=38-(8.723210+\frac{27.40477245}{2})$

$L=38-(8.723210+13.70238622)$

$L=38-(22.42559622)$

$L=15.57440378$

$L\approx 15.57$

Therefore, the dimensions of the window that will maximize the area would be $W\approx 8.72$ and $L\approx 15.57$ .

8 0

3 years ago

What is the population standard deviation of this data set?*

Minchanka [31]

Answer:

C) 2

Step-by-step explanation:

step 1: Find mean of data set

2+4+4+5+7+8 = 30

30/6 = 5

Mean = 5

step 2: subtract each data value from the mean and square it

5-2 = 3; 3² = 9

5-4 = 1; 1² = 1

5-4 = 1; 1² = 1

5-5 = 0; 0² = 0

5-7 = -2; (-2²) = 4

5-8 = -3; (-3²) = 9

Add the squared results:

9+1+1+0+4+9 = 24

Divide 24 by 6 to get the Variance of 4

Take the square root of the Variance to get the Standard Deviation

$\sqrt{4}$ = 2

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3 years ago

Help with my geometry question

Vaselesa [24]

For an inscribed angle like angle AHB, the measure will be half of the intercepted arc which we can see is 90 degrees.. therefore the measure of angle AHB is 45 degrees.

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4 years ago

Type the correct answer in each box

levacccp [35]

Answer:

76589607+789607p8=2

Step-by-step explanation:

3872oed0w89p23-98937ey9tg=2

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3 years ago