The diameter of a circle is 12.6 cm find its perimeter

What is 4 times 1/5 can I have the answer pleas thx

Alja [10]

4 x 1/5 so (1x4)/5 so the answer is 4/5 or .8

8 0

3 years ago

If the work required to stretch a spring 2 ft beyond its natural length is 6 ft-lb, how much work is needed to stretch it 6 in.

mel-nik [20]

Answer:

0.375 feet-lb

Step-by-step explanation:

We have been given that the work required to stretch a spring 2 ft beyond its natural length is 6 ft-lb. We are asked to find the work needed to stretch the spring 6 in. beyond its natural length.

We can represent our given information as:

$6=\int\limits^2_0 {F(x)} \, dx$

We will use Hooke's Law to solve our given problem.

$F(x)=kx$

Substituting this value in our integral, we will get:

$6=\int\limits^2_0 {kx} \, dx$

Using power rule, we will get:

$6=\left[ \frac{kx^2}{2} \right ]^2_0$

$6=\frac{k(2)^2}{2}-\frac{k(0)^2}{2}$

$6=\frac{4k}{2}-0\\\\k=3$

We know that 6 inches is equal to 0.5 feet.

Work needed to stretch it beyond 6 inches beyond its natural length would be $\int\limits^{0.5}_0 {kx} \, dx =\int\limits^{0.5}_0 {3x} \, dx$

Using power rule, we will get:

$\int\limits^{0.5}_0 {3x} \, dx = \left [\frac{3x^2}{2}\right]^{0.5}_0$

$\frac{3(0.5)^2}{2}-\frac{3(0)^2}{2}\Rightarrow \frac{3(0.25)}{2}-0=\frac{0.75}{2}=0.375$

Therefore, 0.375 feet-lb work is needed to stretch it 6 in. beyond its natural length.

3 0

3 years ago

Solve. 3 x+2y−z=8 2x+2z=−4 x+3y=4 Enter your answer, in the form (x,y,z), in the boxes in simplest terms. ( , , )

marshall27 [118]

Answer:

x = 1 , y = 1 , z = -3

Step-by-step explanation:

Solve the following system:

{3 x + 2 y - z = 8

2 x + 2 z = -4

x + 3 y = 4

Hint: | Choose an equation and a variable to solve for.

In the third equation, look to solve for x:

{3 x + 2 y - z = 8

2 x + 2 z = -4

x + 3 y = 4

Hint: | Solve for x.

Subtract 3 y from both sides:

{3 x + 2 y - z = 8

2 x + 2 z = -4

x = 4 - 3 y

Hint: | Perform a substitution.

Substitute x = 4 - 3 y into the first and second equations:

{3 (4 - 3 y) + 2 y - z = 8

2 (4 - 3 y) + 2 z = -4

x = 4 - 3 y

Hint: | Expand the left hand side of the equation 3 (4 - 3 y) + 2 y - z = 8.

3 (4 - 3 y) + 2 y - z = (12 - 9 y) + 2 y - z = 12 - 7 y - z:

{12 - 7 y - z = 8

2 (4 - 3 y) + 2 z = -4

x = 4 - 3 y

Hint: | Expand the left hand side of the equation 2 (4 - 3 y) + 2 z = -4.

2 (4 - 3 y) + 2 z = (8 - 6 y) + 2 z = 8 - 6 y + 2 z:

{12 - 7 y - z = 8

8 - 6 y + 2 z = -4

x = 4 - 3 y

Hint: | Choose an equation and a variable to solve for.

In the first equation, look to solve for y:

{12 - 7 y - z = 8

8 - 6 y + 2 z = -4

x = 4 - 3 y

Hint: | Isolate terms with y to the left hand side.

Subtract 12 - z from both sides:

{-7 y = z - 4

8 - 6 y + 2 z = -4

x = 4 - 3 y

Hint: | Solve for y.

Divide both sides by -7:

{y = 4/7 - z/7

8 - 6 y + 2 z = -4

x = 4 - 3 y

Hint: | Perform a substitution.

Substitute y = 4/7 - z/7 into the second equation:

{y = 4/7 - z/7

8 - 6 (4/7 - z/7) + 2 z = -4

x = 4 - 3 y

Hint: | Expand the left hand side of the equation 8 - 6 (4/7 - z/7) + 2 z = -4.

8 - 6 (4/7 - z/7) + 2 z = 2 z + ((6 z)/7 - 24/7) + 8 = (20 z)/7 + 32/7:

{y = 4/7 - z/7

(20 z)/7 + 32/7 = -4

x = 4 - 3 y

Hint: | Choose an equation and a variable to solve for.

In the second equation, look to solve for z:

{y = 4/7 - z/7

(20 z)/7 + 32/7 = -4

x = 4 - 3 y

Hint: | Isolate terms with z to the left hand side.

Subtract 32/7 from both sides:

{y = 4/7 - z/7

(20 z)/7 = -60/7

x = 4 - 3 y

Hint: | Solve for z.

Multiply both sides by 7/20:

{y = 4/7 - z/7

z = -3

x = 4 - 3 y

Hint: | Perform a back substitution.

Substitute z = -3 into the first equation:

{y = 1

z = -3

x = 4 - 3 y

Hint: | Perform a back substitution.

Substitute y = 1 into the third equation:

{y = 1

z = -3

x = 1

Hint: | Sort results.

Collect results in alphabetical order:

Answer: {x = 1 , y = 1 , z = -3

3 0

3 years ago

hi do I have this answer right? I just need someone help me out with this question so I can get the right answer

Kobotan [32]

I belive his answer is wrong B/c the graph does not even start near 310 the first to bars make it to 50 and 150 so even if u add the two together it would only be 200 so, the answer would be B

6 0

3 years ago

My question is 4318 divided by 7 please tell me

Vikki [24]

1.You should set up the long division.


2 Calculate 43 ÷ 7, which is 6 with a remainder of 1.


3 Bring down 1, so that 11 is large enough to be divided by 7.


4 Calculate 11 ÷ 7, which is 1 with a remainder of 4.

5 Bring down 8, so that 48 is large enough to be divided by 7.


6 Calculate 48 ÷ 7, which is 6 with a remainder of 6.


7 Therefore, 4318 ÷ 7 = 616 with a remainder of 6.

616 with a remainder of 6 or 616.8571

5 0

3 years ago

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The diameter of a circle is 12.6 cm find its perimeter​

The diameter of a circle is 12.6 cm find its perimeter