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
STatiana [176]
3 years ago
6

My Notes 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 f

t/s along a straight path. How fast is the tip of his shadow moving when he is 40 ft from the pole?

Mathematics
2 answers:
Sergio [31]3 years ago
4 0

Answer:

6.667 ft/s

Step-by-step explanation:

Given

Height of street light = 15ft

Height of man = 6ft

Speed away from pole = 4ft/s

Let x represents the distance between the man and the pole, and Let y represents the distance between the tip of the man's shadow to the pole.

This forms a similar triangle (see attachment below).

From similar triangles, we have

(y - x)/6 = y/15 ----- Solve equation

15(y - x) = 6 * y

15y - 15x = 6y ---- Collect Like Terms

15y - 6y = 15x

9y = 15x --- divide through by 9

y = 15x/9

y = 5x/3 ---- differentiate with respect to time, t

dy/dt = 5/3 dx/dt

dx/dt represents rate of change of distance per time = 4ft/s

while dy/dt represents rate of movement of his shadow tips

dy/dt = 5/3 * 4

dy/dt = 20/3 = 6.667 ft/s

likoan [24]3 years ago
4 0

Answer: 6.67ft/s

Step-by-step explanation: PLEASE SEE PICTURE ATTACHED, IT IS A DIAGRAM THAT HELPS YOU TO ANALYSE THE QUESTION.

STEP 1: DEFINE ALL VARIABLES

The man's shadow distance from the pole (Y)

The man's height=6ft

The height of the pole= 15ft

The man's shadow length (X-Y)

The man's speed = 4ft/s

STEP 2: FIND THE MAN'S SHADOW DISTANCE FROM THE POLE (Y)

((X-Y)÷Y) = 6ft÷15ft

Open up bracket and cross multiply

15(X-Y)=6Y

15X-15Y=6Y

collecting like terms together

15X=9Y

Y= 15X/9

Y= 5X/3

STEP 3: FIND THE SPEED OF THE MAN'S SHADOW

Dy/dt = 4ft/s

Therefore

Dy/dx= (4ft/s) × (5X/3)

20ft/3s = 6.67ft/s

The speed of the shadow a cross the pole is 6.67ft/s

You might be interested in
8) Match the graph with the correct set of equations for the linear system.
choli [55]

The system of equations is consistent and dependent.

The system of equations is given as:

  • Equation 1: 3x - 3y =6
  • Equation 2: -x + y = -2.

<h3>The Graph</h3>

Start by plotting the graph of both equations (see attachment)

From the attached graph, we can see that both equations are represented on a single line.

This means that, the system of equations is consistent and dependent.

This is so because, the system of equations have infinite many solutions.

Read more about system of equations at:

brainly.com/question/14323743

3 0
2 years ago
I need help! this is due today!
Andrei [34K]

Answer:

4. 61

5. approximately 43

6. 120

Step-by-step explanation:

4. 80 + 39 = 119

   180 - 119 = 61

5. 7x - 10 = 90

        +10   +10

        7x = 100

divide by 7

x = 14.3

3 times 14.3 = 42.9

6. 70 + 50 = 120

   180 - 120 = 60

   180 - 60 = 120

   

3 0
3 years ago
What is the 5th term of the geometric sequence described by an
FinnZ [79.3K]

Answer:

a_5=25.3125

Step-by-step explanation:

substitute n = 5 into the equation:

a_5=5(1.5)^{5-1}\\a_5=5 \times1.5^4\\a_5=5 \times 5.0625\\a_5=25.3125

3 0
2 years ago
I am having brain fart, I forgot how to do (a+1)^2. I really don't want to go back through my algebra book.
marysya [2.9K]
Use Photomath is all I can say
7 0
3 years ago
ONLY 1% PEOPLE CAN ANSWER THIS QUESTION CORRECTLY 100 points also brainliest
xz_007 [3.2K]

Answer:40b simplified

Step-by-step explanation:

8 0
3 years ago
Other questions:
  • Calculate 85% of 2 500m
    12·2 answers
  • Can u plz help me with this question
    13·2 answers
  • Now imagine that instead of walking along the path 1→2→3→4→1, ann walks 80 meters on a straight line 33∘ north of east starting
    6·2 answers
  • Let f = {(-2.4), (-1,2), (0, 0), (1, -2), (2, -5)}
    5·1 answer
  • Could someone show me how to do this?
    9·1 answer
  • Which are the answers
    10·2 answers
  • Write an equation of the line in point-slope form that passes through the given points.
    8·1 answer
  • What is the slope of the line?
    9·2 answers
  • Order the numbers from greatest to least value.<br> 1.444.<br> 29|13<br> 0.875<br> 47|45
    6·1 answer
  • How do you get 3630 from 726x5 like can you explain it
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!