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
dmitriy555 [2]
3 years ago
7

A spotlight on the ground shines on a wall 12 m away. If a man 2 m tall walks from the spotlight toward the building at a speed

of 1.7 m/s, how fast is the length of his shadow on the building decreasing when he is 4 m from the building?

Physics
1 answer:
mafiozo [28]3 years ago
4 0

Answer:

0.6375 m/s

Explanation:

Let x be the distance of the man from the building

from the figure attached

initially the value of x=12

Given:

\frac{dx}{dt}=-1.7m/s

where the negative sign depicts that the distance of the man from the building is decreasing.

Now, Let The length of the shadow be = y

we have to calculate \frac{dy}{dt} when x=4

from the similar triangles

we have,

\frac{2}{12-x}=\frac{y}{12}    

or

y=\frac{24}{12-x}

Differentiating with respect to time 't' we get

\frac{dy}{dt}=-\frac{24}{12-x}^2\frac{-dx}{dt}

or

\frac{dy}{dt}=\frac{24}{12-x}^2\frac{dx}{dt}

Now for x = 4, and \frac{dx}{dt}=-1.7m/s  we have,

\frac{dy}{dt}=\frac{24}{12-4}^2\times (-1.7)

or

\frac{dy}{dt}=-0.6375m/s

<u>here, the negative sign depicts the decrease in length and in the question it is asked the decreasing rate  thus, the answer is </u><u>0.6375m/s</u>

You might be interested in
Will give big prizes !!
In-s [12.5K]

Answer:

it may be because of the movement of the atoms. i believe that the heat of the warm water makes it move faster, thus making the object float due to upthrust, or air pressure

7 0
2 years ago
How do objects with the same charge interact? How do objects with opposite charges interact?
Marta_Voda [28]
Objects with the same charge repels each other whereas objects with opposite charges attract each other.

Hope this helps!
3 0
3 years ago
Read 2 more answers
Part complete How long must a simple pendulum be if it is to make exactly one swing per five seconds?
shtirl [24]

Answer:

L=6.21m

Explanation:

For the simple pendulum problem we need to remember that:

\frac{d^{2}\theta}{dt^{2}}+\frac{g}{L}sin(\theta)=0,

where \theta is the angular position, t is time, g is the gravity, and L is the length of the pendulum. We also need to remember that there is a relationship between the angular frequency and the length of the pendulum:

\omega^{2}=\frac{g}{L},

where \omega is the angular frequency.

There is also an equation that relates the oscillation period and the angular frequeny:

\omega=\frac{2\pi}{T},

where T is the oscillation period. Now, we can easily solve for L:

(\frac{2\pi}{T})^{2}=\frac{g}{L}\\\\L=g(\frac{T}{2\pi})^{2}\\\\L=9.8(\frac{5}{2\pi})^{2}\\\\L=6.21m

3 0
3 years ago
Need help on this,<br>will mark brainliest if you answer.<br>​
Alecsey [184]

Answer:

(1) tropical storm

(2) Severe tropical storm

(3) 305 kmh

5 0
3 years ago
19. Arrange from smallest to largest: the BTU, the joule, and the calorie.
Papessa [141]

Answer: Don't know sorry

Explanation:

5 0
3 years ago
Other questions:
  • A heavy copper ball of mass 2 kg is dropped from a fiftieth-floor apartment window. Another one with mass 1 kg is dropped immedi
    14·1 answer
  • An airport has a moving walkway in a long corridor (of lengthL) designed to savepassengers time. If Tom walks through the corrid
    5·1 answer
  • For all values of x, y, and z, which expression is equivalent to 5xy. 5z?
    15·2 answers
  • If a cart of 4 kg mass has a force of 8 newtons exerted on it, what is its acceleration
    15·1 answer
  • Beta particles will:
    15·2 answers
  • Express newton pascal joule and watt in fundamental unit​
    10·1 answer
  • What is the momentum of an object weighing 7.5 kg moving at 1.6 m/s?
    9·2 answers
  • EASY QUESTION FOR HIGH SCHOOL TEENS SUPER EASY
    5·2 answers
  • Một nguồn O phát sóng cơ dao động theo phương trình u = 4cos(4pi t - pi/4). Tốc độ truyền sóng là 1m/s.
    12·1 answer
  • A racecar begins at rest and accelerates to 25 m/s at a rate of 6.25 m/s2. What distance does the racecar cover?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!