1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
labwork [276]
3 years ago
12

Whats the perimeter of a semicircle of 6cm​

Mathematics
1 answer:
pashok25 [27]3 years ago
3 0

Answer:

P = 15.42 cm

Step-by-step explanation:

Perimeter of circle = (πD/2)+D

Where D = 6 cm

P =( (3.14)(6)/2) + 6

P = (3.14)(3)+6

P = 9.4 + 6

P = 15.4 cm

You might be interested in
A rocket is fired with an initial vertical velocity of 40 m/s from a launch pad 45 m high, and its height is given by the formul
N76 [4]

Answer:

1) 125 meters

2) For 9 seconds.

Step-by-step explanation:

The rocket's height is given by the formula -5t^2+40t+45.

Notice that this is a quadratic.

Part 1)

Since this is a quadratic, the highest height the rocket goes will be the vertex of our quadratic. Remember that the vertex of a quadratic in standard form is:

(-\frac{b}{2a}, f(-\frac{b}{2a}))

So, let's identify our coefficients. The standard quadratic form is:

ax^2+bx+c

Therefore, in this case, our a is -5, b is 40, and c is 45.

So, let's find the x-coordinate of our vertex. Substitute 40 for b and -5 for a. This yields:

x=\frac{-(40)}{2(-5)}

Multiply and reduce. So:

x=-40/-10=4

Now, substitute 4 for t to find the height. So:

-5(4)^2+40(4)+45

Evaluate:

=-5(16)+40(4)+45

Multiply and add:

=-80+160+45=125\text{ meters}

Therefore, the highest the rocket goes up is 125 meters.

Part 2)

To find out for how much time the rocket is in the air, we can think about after how many seconds after launch will the rocket land.

If the rocket lands, the height h will be 0. So, we can set our expression equal to 0 and solve for t:

-5t^2+40t+45=0

First, let's divide everything by -5. This yields:

t^2-8t-9=0

We can factor:

(t+1)(t-9)=0

Zero Product Property:

t+1=0\text{ or } t-9=0

Solve for t:

t=-1\text{ or } t=9

In this case, since t is our time in seconds, -1 seconds does not make sense. So, we can remove -1 from our solution set.

Therefore, 9 seconds after launch, the rocket will touch the ground.

Therefore, the rocket was in the air for 9 seconds.

And we're done!

6 0
3 years ago
Multiply 4x(-3x - 5)
Scilla [17]
Using the distributive property the product is -12x-20. To distribute you take the numbers and or variables outside of the paranthesis and multiply it by each one in the parenthesis  such that 4x is multiplied by -3x getting -12x and multiplying 4x by -5 and the product is -20x and all together the answer is -12x-20
6 0
3 years ago
Read 2 more answers
5
AveGali [126]

Answer:

Total time taken by walking, running and cycling = 22 minutes.

Step-by-step explanation:

Let the speed of walking = x

As given,

The distance of walking = 1

Now,

As Time = \frac{Distance }{Speed}

⇒ Time traveled by walking = \frac{1}{x}

Now,

Given that - He runs twice as fast as he walks

⇒Speed of running = 2x

Also given distance traveled by running = 1

Time traveled by running = \frac{1}{2x}

Now,

Given that - he cycles one and a half times as  fast as he runs.

⇒Speed of cycling =  \frac{3}{2} (2x) = 3x

Also given distance traveled by cycling = 1

Time traveled by cycling = \frac{1}{3x}

Now,

Total time traveled = Time traveled by walking + running + cycling

                                = \frac{1}{x} +  \frac{1}{2x} + \frac{1}{3x}

                                = \frac{6+3+2}{6x} = \frac{11}{6x}

If he cycled the three mile , then total time taken = \frac{1}{3x} + \frac{1}{3x} + \frac{1}{3x} = x

Given,

He takes ten minutes longer than he would do if he cycled the three miles

⇒x + 10 = \frac{11}{6} x

⇒x - \frac{11}{6} x = -10

⇒-\frac{5}{6}x = -10

⇒x = \frac{60}{5} = 12

⇒x = 12

∴ we get

Total time traveled by walking + running + cycling = \frac{11}{6} x = \frac{11}{6} (12) = 11 (2) = 22 min

7 0
2 years ago
an item is regularly priced at $90 . alan bought it on sale for 30% off the regular price. how much did alan pay?
Minchanka [31]

Answer:

$63

Step-by-step explanation:

100-30=70%

0.7*90=63

3 0
3 years ago
Henry buy 1/4 pounds of screws and 2/5 pounds of nails to build a skateboard ramp what is the total weight of the screws and nai
iren2701 [21]

the total weight of the screws and nails is \frac{13}{20} pounds

7 0
3 years ago
Other questions:
  • How do i solve v=pi/3*r (squared)h for h
    6·1 answer
  • Mike and Beth are saving money to go to Disneyworld. They need at least $1975 in order to go. Mike mows yards and Beth will wash
    11·1 answer
  • May you please help me with this problem
    7·2 answers
  • Determine if the triangles are congruent.
    9·1 answer
  • 2.Rosa has a goal of running a total of 150 miles this month to prepare for a race. Each day she runs 7 miles. She wants to know
    14·1 answer
  • {HELP ASAP }WILL GIVE 50+ POINTS AND BRAINLIEST
    14·1 answer
  • ABCD is a rhombus and DB=10 Find the length of DC
    15·1 answer
  • Can someone please help me?
    5·2 answers
  • The coffee shop has 5 regular customers daily. On Saturday they have 6 times as many non-regular customers than on any given wee
    5·1 answer
  • Ben paid $45 for an old guitar he cleaned the guitar, then resold it after marking the price 15% he used 36% of the money he got
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!