On a test each student is given a grade of a b c d or f witch measure tells the grade given most often

The observation deck of the willis tower in Chicago Illinois is 1353 feet above the ground elevators lift visitors to that level

Paul [167]

Answer: The the speed of elevators is 22.55.

Explanation:

It is given that observation deck of the willis tower in Chicago Illinois is 1353 feet above the ground elevators lift visitors to that level in 60 seconds.

The speed is the change in distance with respect to time.

$\text{Average Speed}=\frac{\text{Total Distance}}{\text{Total Time}}$

From the given information the total distance is 1353 and the total time is 60 seconds. So by the above formula we get,

$\text{Average Speed}=\frac{1353}{60}$

$\text{Average Speed}=22.55$

Therefore, the speed of elevators is 22.55.

8 0

3 years ago

A carpenter wants to cut a board 16 1/2 feet in length into 1 7/8 feet pieces. How many pieces can be cut from the board? The ca

yawa3891 [41]

<h3>Answer:</h3>

8 pieces
3/8 foot

<h3>Explanation:</h3>

a) Let n represent the number of 1 7/8 ft pieces. Then we have ...

... 16 1/2 ft = n × (1 7/8 ft)

We can find n by dividing this equation by 1 7/8.

... (16 1/2)/(1 7/8) = n = (132/8)/(15/8) = 132/15

... n = 8 12/15 = 8 4/5

The integer number of pieces that can be cut is 8 pieces.

b) The length of the left-over piece is 4/5 of the full length of a piece, so is ...

... (4/5) × (15/8 ft) = 12/8 ft

We want to divide this into 4 equal lengths, so each of those lengths will be 1/4 of the length of the left-over:

... (1/4) × (12/8 ft) = 3/8 ft

_____

<em>Comment on arithmetic with fractions</em>

This problem is easier if you <em>convert the mixed numbers to improper fractions</em>. This is done by expressing the integer as a number of fractional parts, then adding the fraction part of the mixed number:

... a + b/c = (a×c/c) + b/c = (ac +b)/c

Division with fractions is taught a couple of different ways. One way you can do it is to "invert and multiply". That is, you multiply the numerator fraction by the reciprocal of the denominator fraction:

... (a/b)/(c/d) = (a/b)×(d/c)

Another way you can do the division is to express each of the numerator and denominator fractions over the same denominator. Then the quotient is the ratio of numerators.

... (a/c)/(b/c) = a/b

This is the method we used here. Effectively, we converted 16 1/2 to 16 4/8 then to (16×8 +4)/8 = 132/8. Then the numerator and denominator fractions both had denominators of 8, so (132/8)/(15/8) = 132/15. This fraction can be reduced by removing a factor of 3 from numerator and denominator to give ...

... 132/15 = 44/5 = 8 4/5

7 0

3 years ago

If J is the centroid of cde, de=52, fc=15, he=14, find each missing measure

const2013 [10]

Answer:

$DG = 26$

$GE = 26$

$DF = 15$

$CH = 14$

$CE = 28$

Step-by-step explanation:

The figure has been attached, to complement the question.

$DE = 52$

$FC = 15$

$HE = 14$

Given that J is the centroid, it means that J divides sides CD, DE and CE into two equal parts respectively and as such the following relationship exist:

$DF = FC$