Simplify and round the expression below. C isn’t necessary to answer

I beg of you solve it. A small Plane can travel 120 mph in still air. The plain can fly 700 miles with the wind in the same that

Fiesta28 [93]

Answer:

speed of the wind, w = 20 mph

Step-by-step explanation:

Let,

s = speed in still air = 120 mph

w = wind speed = ?

t = travel time in hours

Plane traveling with the wind, we have:

(v + w)t = 700

(120 + w)t = 700 ------------------(equation 1)

Plane traveling against the wind, we have:

(v - w)t = 500

(120 - w)t = 500 --------------------(equation 2)

From equation 1, make t subject of formula,

t = 700/(120 + w) -------------------(equation 3)

From equation 2, make t also subject of formula,

t = 500/(120 - w) ---------------------(equation 4)

It is the same t in both equations, so equating equation 3 and 4

700/(120 + w) = 500/(120 - w)

Solve for w.

500(120 + w) = 700(120 - w)

60000 + 500w = 84000 - 700w

500w + 700w = 84000 - 60000

1200w = 24000

w = 24000/1200

w = 20 mph

3 0

3 years ago

Situation:

Rzqust [24]

N=NOe^-kt
N=mass at time t
NO = initial mass
k= 0.1476
t= time, in days

We are asked to find the half-life, which means you want to find how long it will take for half of the substance to decay/disappear (depending on situation).

If we are looking for half-life, we can simply set N to half of NO (which we are given a value of 40grams for)
Therefore:
N = 20
NO = 40
plugging these values and the value given for k back into the equation you get:

20 = 40e^-0.1476(t)
We are looking for t, so we have to manipulate the formula to get t by itself on one side of the equation.
We can start by dividing 40 from both sides, and you get:
0.5 = e^-0.1476(t)

We have the exponential function "e".
To get rid of e, we can use natural log (ln)
if e^y=x then ln (x) = y
look back at our equation we can set
0.5 = x
-0.1476(t) = y

Rewriting it in natural log form:
ln (0.5) = -0.1476(t)
Plug in ln (0.5) on a calculator to find its value and we get:
-0.693147 = -0.1476(t)
*Note: normally, getting a negative value would suggest that we did something wrong, because you cannot have a negative value as your t (you cannot have negative days), but because there is a negative on both sides of the equation, they will cancel out in this case.

The last step is to simply divide both sides by -0.1476
therefore:
T = 4.696119
But it asks you for the answer to the nearest tenth (one place after decimal pt) so
T (half life) = 4.7 days

Hope that helps :)

8 0

4 years ago

Solve If QR = 6x + 1, PR = 14x - 13, and PQ = 5x - 2, find PR

solong [7]

Answer:

P____Q____R

PR= PQ+ QR

(14x-13) = (5x-2)+(6x+1)

14x-13= 11x – 1

14x – 11x = 13–1

3x = 12

x= 12/ 3

x= 4

PR= 14x – 13 = 14 (4) – 13 = 18 – 13= 5

If you want (PQ , QR ) this is the solution

PQ =5x-2=5(4)-2=20-2=18

QR =6x+1=6(4)+1=24+1=25

I hope I helped you^_^

7 0

3 years ago

40 Points! PLS HELP

const2013 [10]

The area of the square is 9 in^2

The side of a square is the square root of the area.

Side of square = √9 = 3 inches.

The side of the square is the diameter of the inscribed circle.

Circumference of a circle is PI x diameter.

Circumference of inscribed circle = 3.14 x 3 = 9.42 inches

The diameter for the circumscribed circle would be the diagonal of the square which is 3√2 = ( Side length x √2) ≈ 4.2426

The circumference = 3.14 x 3√2 = 13.321

Find the ratio between the two circles:

Circumscribed / inscribed =

13.321 / 9.42 = 1.41

5 0

4 years ago

If you invest $1500 in at an interest rate of 7% for 5 years and the interest is compounded quarterly, how much money will you h

Flauer [41]

100%+7%=107% 1.07³x1.07²x1500=2103.83

7 0

3 years ago