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2 years ago

Last question of a really important test! I really need some help!

Mathematics

1 answer:

Ket [755]2 years ago

4 0

Last question of a really important test! I really need some help!

A hollow ball is made of rubber that is 1 centimeter thick. The ball has a radius of 5 centimeters at the outside surface.

What is the approximate volume of rubber used to make the ball?

Use 3.14 for pi.

255.4 cm³

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Is this a function. ?

goldenfox [79]

Answer:

Step-by-step explanation:

4 0

2 years ago

y = c1 cos(5x) + c2 sin(5x) is a two-parameter family of solutions of the second-order DE y'' + 25y = 0. If possible, find a sol

TEA [102]

Answer:

y = 2cos5x-9/5sin5x

Step-by-step explanation:

Given the solution to the differential equation y'' + 25y = 0 to be

y = c1 cos(5x) + c2 sin(5x). In order to find the solution to the differential equation given the boundary conditions y(0) = 1, y'(π) = 9, we need to first get the constant c1 and c2 and substitute the values back into the original solution.

According to the boundary condition y(0) = 2, it means when x = 0, y = 2

On substituting;

2 = c1cos(5(0)) + c2sin(5(0))

2 = c1cos0+c2sin0

2 = c1 + 0

c1 = 2

Substituting the other boundary condition y'(π) = 9, to do that we need to first get the first differential of y(x) i.e y'(x). Given

y(x) = c1cos5x + c2sin5x

y'(x) = -5c1sin5x + 5c2cos5x

If y'(π) = 9, this means when x = π, y'(x) = 9

On substituting;

9 = -5c1sin5π + 5c2cos5π

9 = -5c1(0) + 5c2(-1)

9 = 0-5c2

-5c2 = 9

c2 = -9/5

Substituting c1 = 2 and c2 = -9/5 into the solution to the general differential equation

y = c1 cos(5x) + c2 sin(5x) will give

y = 2cos5x-9/5sin5x

The final expression gives the required solution to the differential equation.

3 0

3 years ago

A recent survey showed that 23.3 million adults have cut the cord on cable TV services, a 30% increase fron the previous year. I

sesenic [268]

Answer:

30,290,000 people

Step-by-step explanation:

The question is asking if the trend continues from the PREVIOUS year, so we would find the 30% of 23,300,000

23,300,000/100 = 233,000 = 1%

233,000 x 30 = 6,990,000

23,300,000 = 6,990,000 = 30,290,000

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3 years ago

Shelby bought a 2-ounce tube of blue paint. She used 2/3 ounce to paint the water, 3/5 ounce to paint the sky, and some to paint

irina1246 [14]

Answer:

The amount of ounce used for paint is $\frac{9}{15} ounce$

Step-by-step explanation:

used amount for water is $\frac{2}{3}$ ounce.

used amount for sky is $\frac{3}{5}$ ounce.

thus, the total amount used is $\frac{2}{3}$ + $\frac{3}{5}$

= $\frac{19}{15}$

Thus the total unused amount is 2 - $\frac{19}{15}$ = $\frac{11}{15}$ .

But the remaining amount is $\frac{2}{15}$ .

Thus used amount for flag is $\frac{11}{15}$ - $\frac{2}{15}$

= $\frac{9}{15}$

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3 years ago

Need the answer asap !! #34 !!

Rus_ich [418]

Answer:

A) 46 mph

Step-by-step explanation:

Step 1: To find the speed, you need to find the distance and time to travel between Chicago and Cleveland.

Distance = 354 miles

Time = 9: 50 am to 5: 30 pm

Time = 7 hours 40 minutes

Step 2: Convert time to hours

1 hour = 60 minutes

40 minutes = 60/40 = 2/3 hours

Step 3: Find the speed

Speed = Distance/Time

Speed = 354/7 + 2/3

Speed = 1062/23

Speed = 46.17 miles per hour rounded off to 46 mph

Therefore, A is the correct answer.

5 0

3 years ago