List all positive factors for each 30-18

A box with a square base and open top must have a volume of 296352 c m 3 . We wish to find the dimensions of the box that minimi

mestny [16]

Answer:

Base Length of 84cm
Height of 42 cm.

Step-by-step explanation:

Given a box with a square base and an open top which must have a volume of 296352 cubic centimetre. We want to minimize the amount of material used.

Step 1:

Let the side length of the base =x

Let the height of the box =h

Since the box has a square base

Volume, $V=x^2h=296352$

$h=\dfrac{296352}{x^2}$

Surface Area of the box = Base Area + Area of 4 sides

$A(x,h)=x^2+4xh\\$Substitute h=\dfrac{296352}{x^2}\\A(x)=x^2+4x\left(\dfrac{296352}{x^2}\right)\\A(x)=\dfrac{x^3+1185408}{x}$

Step 2: Find the derivative of A(x)

$If\:A(x)=\dfrac{x^3+1185408}{x}\\A'(x)=\dfrac{2x^3-1185408}{x^2}$

Step 3: Set A'(x)=0 and solve for x

$A'(x)=\dfrac{2x^3-1185408}{x^2}=0\\2x^3-1185408=0\\2x^3=1185408\\$Divide both sides by 2\\x^3=592704\\$Take the cube root of both sides\\x=\sqrt[3]{592704}\\x=84$

Step 4: Verify that x=84 is a minimum value

We use the second derivative test

$A''(x)=\dfrac{2x^3+2370816}{x^3}\\$When x=84$\\A''(x)=6$

Since the second derivative is positive at x=84, then it is a minimum point.

Recall:

$h=\dfrac{296352}{x^2}=\dfrac{296352}{84^2}=42$

Therefore, the dimensions that minimizes the box surface area are:

Base Length of 84cm
Height of 42 cm.

5 0

3 years ago

Tanya is training a turtle for a race. For every 1/2 of an hour that the turtle is crawling, he can travel 3/20 of a mile. At wh

vazorg [7]

Answer:

$\frac{6}{20} \ mile\ per\ hour$

Step-by-step explanation:

Given:

For every 1/2 of an hour that the turtle is crawling, he can travel 3/20 of a mile

Question asked:

At what unit rate is the turtle crawling?

Solution:

As here<u> time taken is given</u> and the <u>distance traveled is also given </u>and hence we will apply speed and distance formula to find rate of crawling of turtle.

Time taken by turtle = $\frac{1}{2} \ hour$

Distance which can be traveled by turtle = $\frac{3}{20} \ miles$

$Speed =\frac{Distance}{Time}$

$=\frac{3}{20} \div\frac{1}{2} \\\\ =\frac{3}{20} \times\frac{2}{1} \\ \\ =\frac{6}{20}$

Therefore, the rate at which the turtle is crawling is $\frac{6}{20} \ mile\ per\ hour$

4 0

3 years ago

The length of the rectangle is twice the width. Find the length of the rectangle if the perimeter is 42m.

kompoz [17]

Answer:

28m

Step-by-step explanation:

2x+x=42

3x=42

x=14

However, since the length of the rectangle is twice the width, we'll need to multiply it by 2.

So: 14 times 2=28

8 0

3 years ago

28.)Find the value of x.320(3x-10°A.) x = 22.67B.) x = 34.67C.) x = 21.6D.) x = 24.25

katen-ka-za [31]

Since the big triangle is an isosceles one, we conclude that the angles of the left triangle are: 32, 90 and 3x-10. Sinche the sum of this angles have to be 180° we have: