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
Norma-Jean [14]
3 years ago
11

A 71 kW radio station broadcasts its signal uniformly in all directions. - What is the average intensity of its signal at a dist

ance of 220 m from the antenna? -What is the average intensity of its signal at a distance of 2200 m from the antenna?
Physics
1 answer:
marshall27 [118]3 years ago
3 0

Answer:

Explanation:

Energy of signal being radiated per second on all sides = 71 x 10³ J .

At a distance of 220 m it is spread over an area of 4 π x (220)² because it is spreading uniformly on all sides.

So energy crossing per unit area

= \frac{71\times10^3}{4 \times \pi\times(220)^2}

= 11.67 x 10⁻² Wm⁻²s⁻¹.

This is the intensity of the signal.

At 2200 m this intensity will further reduce by 100 times

So there it becomes equal to

11.67 x 10⁻⁴ Wm⁻² s⁻¹.

You might be interested in
Question 14 of 30
docker41 [41]

Answer: a.

Explanation: i have done this before .. hope this helps (⌐■_■)

6 0
3 years ago
Read 2 more answers
The closest distance a book can be read from a pair of reading eyeglasses (Power = 1.55 dp) is 26.0 cm. What is the near distanc
Mnenie [13.5K]

Answer:

The image distance is 20.0 cm.

Explanation:

Given that,

Power = 1.55 dp

Distance between book to eye = 26.0+3.00=29.0 cm

We need to calculate the focal length

Using formula of focal length

f = \dfrac{1}{P}

Put the value into the formula

f=\dfrac{1}{1.55}

f=0.645\ m

f=64.5\ cm

We need to calculate the image distance

Using lens formula

\dfrac{1}{f}=\dfrac{1}{u}+\dfrac{1}{v}

\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{-u}

Put the value into the formula

\dfrac{1}{v}=\dfrac{1}{64.5}-\dfrac{1}{-29}

\dfrac{1}{v}=\dfrac{187}{3741}

v=20.0\ cm

Hence, The image distance is 20.0 cm.

5 0
3 years ago
Show how the alternative definition of power, found in your book, can be derived by substituting the definitions of work and spe
Harman [31]

Let us consider body moves a distance S due to the force F.

Hence the work by the body W = FS

If the force is not along the direction of displacement,then the work by a body for travelling a distance S will be -

                                       W=[ Fcos\theta]*S  where    Fcos\theta is the component of the force along the direction of displacement.

                                  Hence\ W= FScos\theta

                                                        = F.S

As per the question the power P is given as -

                                                  P=\frac{W}{\delta t}

                                                         =\frac{F.S}{\delta t}

                                                         = F.\frac{S}{\delta t}

                                                         = \ F.V

Hence alternative definition of power P = F.V


8 0
3 years ago
Read 2 more answers
What gravitational force does the earth exert on a person
lara [203]

The  gravitational force exerted by the earth on a person standing on the earth's surface is 602.74 N.

<h3>What is the gravitational force of the earth on the person?</h3>

The gravitational force exerted by the earth on a person standing on the earth's surface is given below as follows:

  • F = \frac{Gm^{1}m^{2}}{r^{2}}

where

G = 6.67 * 10⁻¹¹

m¹ = 62 kg

m² = 5.97 * 10²⁷ kg

r = 6.4 * 10⁶ m

F = \frac{5.97*10^{24}*62*6.67*10^{-11}}{(6.4*10^{6}){2}} = 602.74\:N

Therefore, the gravitational force exerted by the earth on a person standing on the earth's surface is 602.74 N.

Learn more about gravitational force at: brainly.com/question/940770

#SPJ1

7 0
2 years ago
Adding or removing thermal energy to or from a substance does not always cause its temperature
julia-pushkina [17]
Change in thermal energy not always cause it's temperature change. It is the situation when water reaches either at 0 C or 100 C then thermal energy doesn't cause change in temperature instead it changes the state of matter.

In short, Your Answer would be "True"

Hope this helps! 
6 0
3 years ago
Read 2 more answers
Other questions:
  • The gas tank of a car is filled with a nozzle that discharges gasoline at a constant flow rate. Based on unit considerations of
    12·1 answer
  • A 5510 kg space probe, moving nose-first toward Jupiter at 250 m/s relative to the Sun, fires its rocket engine, ejecting 75.0 k
    7·1 answer
  • Nevermindddddddddddd
    9·1 answer
  • Microwelds are formed where
    8·2 answers
  • A 1.15-kg mass oscillates according to the equation where x is in meters and in seconds. Determine (a) the amplitude, (b) the fr
    9·1 answer
  • how can you find the mechanical advantage of the six different simple machines? (simples mechinals are pulleys, inclined plane,
    9·1 answer
  • What do your joints do?
    12·2 answers
  • The combination of an applied force and a friction force produces a constant torque of 36.0 N⋅m on a wheel rotating on a fixed a
    11·1 answer
  • A 20 kg cart moving at 4 m/s has how much momentum?
    5·1 answer
  • How many wavelengths are represented​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!