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4 years ago

What is the circumference of a circle with radius pi?

Mathematics

1 answer:

vfiekz [6]4 years ago

6 0

Answer:

2π² or 19.74

Step-by-step explanation:

Circumference of a circle is C = 2πr

Given r = π

Then:

C= 2π*π = 2π²

≈19.74

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Write the quantity as percentage of the second (give answers to the nearest whole number).

GarryVolchara [31]

Answer:

Step-by-step explanation:

We need our two numbers to have the same units. Since one number is in cents and the other is in dollars, we should change one of them. It could be either one.

Both numbers in cents:

50/4000

OR, both numbers in dollars:

.50/40.00

Either of these will work. Divide, you will get a decimal answer. Then multiply by 100 to change to a percent.

50÷4000 (OR .5/40)

= 0.0125

times by 100

0.0125 × 100

= 1.25% but the directions said to round to the nearest whole number, that's 1%

4 0

1 year ago

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Convert 10.3 cm into m

IRISSAK [1]

Answer:

10.3cm=0.103

Step-by-step explanation:

Hope this helped :)

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7 0

3 years ago

Read 2 more answers

1 pint = ____ cups

katovenus [111]

Answer:

2, 4, 2, 8, 16

Step-by-step explanation:

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3 years ago

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a port and a radar station are 2 mi apart on a straight shore running east and west. a ship leaves the port at noon traveling no

Rom4ik [11]

Answer:

The rate of change of the tracking angle is 0.05599 rad/sec

Step-by-step explanation:

Here the ship is traveling at 15 mi/hr north east and

Port to Radar station = 2 miles

Distance traveled by the ship in 30 minutes = 0.5 * 15 = 7.5 miles

Therefore the ship, port and radar makes a triangle with sides

2, 7.5 and x

The value of x is gotten from cosine rule as follows

x² = 2² + 7.5² - 2*2*7.5*cos(45) = 39.04

x = 6.25 miles

By sine rule we have

$\frac{sin A}{a} = \frac{sin B}{b}$

Therefore,

$\frac{sin 45}{6.25} = \frac{sin \alpha }{7.5}$

α = Angle between radar and ship α

∴ α = 58.052

Where we put

$\frac{sin 45}{6.25} = \frac{sin \alpha }{x}$ to get

$\frac{x}{6.25} = \frac{sin \alpha }{sin 45}$ and differentiate to get

$\frac{\frac{dx}{dt} }{6.25} = cos\alpha\frac{\frac{d\alpha }{dt} }{sin 45}$

$\frac{15sin45 }{6.25cos\alpha } =\frac{d\alpha }{dt} }$ = 3.208 degrees/second = 0.05599 rad/sec.

6 0

3 years ago

The area of a circular oil slick on the surface of the sea is increasing at a rate of [150m^2/s] how fast is the radius changing

Akimi4 [234]

Answer with Step-by-step explanation:

We are given that

$\frac{dA}{dt}=150m^2/s$

a.Radius =25 m

We have to find rate of change of radius.

We know that

Area of circle, $A=\pi r^2$

Differentiate w.r.t time

$\frac{dA}{dt}=2\pi r\frac{dr}{dt}$

Substitute the values then we get

$150=2\pi (25)\frac{dr}{dt}$

$\frac{dr}{dt}=\frac{150}{50\pi}=\frac{3}{\pi} m/s$

$\frac{dr}{dt}=\frac{3}{\pi} m/s$

b.A= $1000m^2$

Substitute the values then we get

$1000=\pi r^2$

$\pi=3.14$

$r^2=\frac{1000}{3.14}$

$r=\sqrt{\frac{1000}{3.14}}=17.8m$

$\frac{dA}{dr}=2\pi r\frac{dr}{dt}$

Substitute the values then we get

$150=2\pi(17.8)\frac{dr}{dt}$

$\frac{dr}{dt}=\frac{150}{2\pi(17.8)}=\frac{150}{35.6\pi}$ m/s

$\frac{dr}{dt}=\frac{75}{17.8\pi}$ m/s

4 0

3 years ago

What is the circumference of a circle with radius pi?​

What is the circumference of a circle with radius pi?