Find the value of x.<br> (2x + 3)<br> 100°<br> 199

A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft tall walks away from the pole with a speed of 4 ft/s along

mina [271]

Answer:

The tip of the man shadow moves at the rate of $\frac{20}{3} ft.sec$

Step-by-step explanation:

Let's draw a figure that describes the given situation.

Let "x" be the distance between the man and the pole and "y" be distance between the pole and man's shadows tip point.

Here it forms two similar triangles.

Let's find the distance "y" using proportion.

From the figure, we can form a proportion.

$\frac{y - x}{y} = \frac{6}{15}$

Cross multiplying, we get

15(y -x) = 6y

15y - 15x = 6y

15y - 6y = 15x

9y = 15x

y = $\frac{15x}{9\\} y = \frac{5x}{3}$

We need to find rate of change of the shadow. So we need to differentiate y with respect to the time (t).

$\frac{dy}{t} = \frac{5}{3} \frac{dx}{dt}$ ----(1)

We are given $\frac{dx}{dt} = 4 ft/sec$ . Plug in the equation (1), we get

$\frac{dy}{dt} = \frac{5}{3} *4 ft/sect\\= \frac{20}{3} ft/sec$

Here the distance between the man and the pole 45 ft does not need because we asked to find the how fast the shadow of the man moves.

7 0

3 years ago

HELP ASAP PLEASE 15P

UNO [17]

Answer:

4

Step-by-step explanation:

It goes through that one on the graph

8 0

3 years ago

Read 2 more answers

Calculate the distance between each given pair of points. Round your answer to the nearest tenth, if necessary.

Ksju [112]

The answer is 5

Here are the steps:

First off, we will be using the distance formula of
$d=\sqrt{(x_ {2}- x_{2}) ^{2}+( y_{2}- y_{1})^2 }$

So we have the ordered pairs of (3,1) and (6,5)

Once you plug them into the formula it should look like this:
$d= \sqrt{(6-3)^2+(5-1)^2}$

Now we do the math inside the parenthesis and end up with:
$d=\sqrt{3^2+4^2}$

Then you multiply by the power and simplify to get:
$d=\sqrt{25}$

And the $\sqrt{25}$ =5

So your answer is 5

8 0

3 years ago

the numbers of girls in the choir is 4 times the number of boys in the choir .the total number of students is 60..how many girls

Inessa05 [86]

First, make up some variables to represent the number of Girls and Boys in the choir.

B = number of boys
G = number of girls

You know that there are 4 times as many girls in the choir as boys. Therefore, the equation you can write is:
$\frac{B}{G} = \frac{1}{4}$

If you cross-multiply, then you get the simplified equation:
G = 4B

Intuitively this makes sense since if you multiplied the number of boys in the class by 4, that would be equal to the number of girls you have.

Now, we know that the total class size is 60. So girls plus boys equals 60:
G+B = 60

To solve the equation, replace the G in this equation with the replacement you found before, 4B.
G + B = 60 -->
4B + B = 60 -->
5B = 60 -->
B = 12

However, you are trying to find the number of girls, so plug the answer back into your equation.
G + B = 60 -->
G + 12 = 60 -->
G + 12 -12 = 60 - 12 -->
G = 48

The number of girls you have is 48.

6 0

3 years ago

A way to write numbers by showing the digits 0-9 with each digit having a place value

ExtremeBDS [4]

0 has none and 9 has 9 place value i think lol

4 0

3 years ago

Find the value of x. (2x + 3) 100° 199