890 g of copper is mixed with 100 g of zinc to form brass. The density of copper is 8.9 g/cm³ and the density of zinc is 7.1 g / cm ³ .

a ) What is the volume of copper and zinc used to make the brass ?
b ) Calculate the density of the brass . ​

Answer:

took me time to try and answer your question hope it proves helpful

Answer:

The answer is below

Step-by-step explanation:

The electrical resistance R of a wire varies inversely with the square of its diameter d:

R ∝ 1 / d

Let k represent the constant of proportionality, hence we can represent the statement as an equation:

[tex]R=\frac{k}{d^2}\\ \\when\ R=0.5 \Omega,d=2\ mm\\\\0.5=\frac{k}{2^2} \\\\k=2\\\\The\ equation\ becomes :\\\\R=\frac{2}{d^2}\\ \\When\ d=3, we\ find\ R\\\\R=\frac{2}{3^2} \\\\R=0.22\ \Omega[/tex]

Answer:

The constant of proportionality is 2 it is y=2x

Step-by-step explanation:

Each time the number goes up it goes up by two i hope this helps have a nice day

Answer:

f(x) is always 5.

Step-by-step explanation:

The formula has a fixed value. Y is the f(x) in the function, and since there is no X, then Y is as said: 5. For example, when X is -7, the f(x), or Y, is still 5, and so on.

Answer:

D. 58

Step-by-step explanation:

pretty easy clap

bisecting is midpoint which makes the two angles congruent

Answer:

There are 12 left-handed players in the league

Step-by-step explanation:

Let us solve the problem

∵ A local little league has a total of 60 players

∵ 20% of them are left-handed

→ Find 20% of 60

∴ The number of left-handed players = 20% × 60

→ Change 20% to a decimal

∵ 20% = [tex]\frac{20}{100}[/tex] = 0.20

∴ The number of left-handed players = 0.20 × 60

∴ The number of left-handed players = 12

∴ There are 12 left-handed players in the league

By "limit definition", I assume you mean the derivative. We have

[tex]f'(c) = \displaystyle\lim_{x\to c}\frac{f(x)-f(c)}{x-c}[/tex]

For [tex]f(x)=\frac1{x-1}[/tex] and c = 2, we have

[tex]f'(2)=\displaystyle\lim_{x\to2}\frac{\frac1{x-1}-1}{x-2}[/tex]

[tex]f'(2)=\displaystyle\lim_{x\to2}\frac{\frac{1-(x-1)}{x-1}}{x-2}[/tex]

[tex]f'(2)=\displaystyle\lim_{x\to2}\frac{2-x}{(x-1)(x-2)}[/tex]

[tex]f'(2)=\displaystyle\lim_{x\to2}\frac1{1-x}=-1[/tex]

The tangent line to (2, 1) has slope -1. Using the point-slope formula, it has equation

y - 1 = - (x - 2)

y = - x + 3

Answer:

3^7

Step-by-step explanation:

27 = 3^3

81 = 3^4

3+4 = 7

Simple answer.

You will have to replace a, with the given numbers.

For the 1st one)

70-25² since a=25. 70-625=-55

2nd)

70-1²=70-1=69

3d)

70-10²=70-100=-30

Hope this helped.

Answer:

Step-by-step explanation:

132 / 4 = 33

Therefore,

The answer is,

Answer:

7/20

Step-by-step explanation:

Answer:

Step-by-step explanation:

Thank you ☺️☺️☺️

Answer:

5x-y +42=0

Step-by-step explanation:

Using m=Y2- Y1

X2- X1

the slope of the line is found .

Put your answer in Y - Y1 = m( X - X1)

to get the equation

Answer is 2/3

Hope this helps

Answer:

The surface area of the log including the ends and the inside is 80424.8 cm²

Step-by-step explanation:

To determine the surface area of the log with hollow center including the ends and the inside, we will find the surface area of the outer part of the log, surface area of the inner part of the log and the surface area of the two ends; and then sum everything up.

From the question,

Diameter of log = 60 cm

Length of log = 3 m = 300 cm

Diameter of hollow center = 20 cm

For the surface area of the outer part,

Area of the outer part = Circumference of the outer part × length

Circumference = 2πr = πd

∴ Area of the outer part = πd × l

(NOTE: d here is the diameter of the log)

d = 60 cm and l = 300 cm

Area of the outer part = 60π × 300 = 18000π cm²

For the surface area of the inner part,

Area of the inner part = Circumference of the inner part × length = πd × l

(NOTE: d here is the diameter of the hollow center)

d = 20 cm and l = 300 cm

Area of the inner part = 20π × 300 = 6000π cm²

For the surface area of one end

This is the difference between the area of the outer end and the area of the inner end

Here, we can determine the area by using

Area = πr², where r is the radius

Radius = Diameter / 2

Radius of outer end (R) = Diameter of log / 2 = 60cm / 2 = 30cm

Radius of inner end (r) = Diameter of hollow center / 2 = 20cm / 2 = 10 cm

∴ Surface area of one end = πR² - πr² = π(R²-r²)

= π (30²-10²)

= π (900 - 100)

= 800π cm²

This is the area of one end

For the two ends,

Area of the two ends = 2 × 800π cm² = 1600π cm²

Hence, the surface area of the log is 18000π cm² + 6000π cm² + 1600π cm²

Surface area of the log = 25600π cm²

Putting the value of π (π = 3.141592654)

Surface area of the log = 25600 × 3.141592654 cm²

Surface area of the log = 80424.77193 cm²

Surface area of the log = 80424.8 cm²

Hence, the surface area of the log including the ends and the inside is 80424.8 cm² (to one decimal place)

Answer:

Step-by-step explanation: the first time you get 0.75 and the second time you get 0.125 hope this helped

Answer:

0.712 cents per pound

Step-by-step explanation:

Since we are given the exact amount of each ingredient as well as the price for that amount then we simply need to calculate how much each pound of the confetti actually costs. We do this by adding together all of the pound of all of the ingredients and then adding together all of the costs. Lastly, we divide the cost by the total amount of pounds to find the cost per pound of the confetti like so...

3lbs. + 5lbs. + 3lbs. = 11 lbs.

$2.46 + $3.05 + $2.33 = $7.84

$7.84 / 11 lbs. = 0.712 cents per pound

Therefore, the cost per pound of the confetti is 0.712 cents per pound

Answer:

B and C are similar to A but E is same as A.

Answer:

The next three terms are 55,89 and 144

Step-by-step explanation:

We want to predict the next three numbers in the pattern

3, 5, 8 , 13 , 21 , 34

The difference between two successive terms is written between them.

Thus, we have

3 2 5 3 8 5 13 8 21 13 34

So the rule here is to add the next term to the previous so as to get the next coming term

Thus, we have;

34 + 21 = 55

55 + 34 = 89

89 + 55 = 144

Answer:

i would say a but i could be wrong

Step-by-step explanation:

Answer:

6

Step-by-step explanation:

A way to answer these questions like I usually do is to subtract the result by the number you already know, like this;    10-4=6, so 6 would be what X equals, or you can just take the long way and keep guessing what the answer would be and keep doing the problems, but that would be very time consuming so I would recommend just doing the subtraction method!

Hope this helps!

Answer:

x = 6

Step-by-step explanation:

x + 4  = 10

=> x = 10 - 4

=> x = 6

Answer:

it can grow .125 inches an hour

Step-by-step explanation:

if thats not what u were looking for commet it and ill try to help more

Answer:

.125 inches per hour

Step-by-step explanation:

you divide .25 by 24, since there are 24 hours in a day and get .0104.... and then you multiply that by 12, since there are 12 inches in a foot and get .125 inches per hour.

Answer:

Piecewise functions are functions that behave differently in different regions of the domain.

One example that you may see in your city is the case of the street illumination, such that can be modeled as:

x = time

Suppose that the lights are turned on at a given hour x0 and then turn off at the hour x1, we can define:

f(x) = 0 if x1 < x < x0

f(x) = 1 if x0 ≤ x ≤ x1

Where f(x) represents the intensity of the light at the time x.

Between x1 and x0, the lights are not working, so the illumination that they provide is zero.

Between x0 and x1 the lights are turned on, so the illumination is 1.

Another example can be the accurate description of the velocity of a car as a function of time.

For some pieces, the car will be stopped (maybe in a red light)

For some pieces, the car will be moving slow (maybe there is a lot of traffic)

For some pieces, the car will be moving fast or accelerating (in an empty street).

So we can define this motion as a piecewise function that obviously will depend on how the car moves.

Answer:

there are 30 boys

Step-by-step explanation:

If there is 24 girls you divide that by 4 and you get six so that means you multiply with six and you get 30.

A ratio of 4:5 means that for every 4 girls, there are 5 boys.

24 girls / 4 girls = 6

5 * 6 = 30 boys

There are 30 boys if there are 24 girls