1. How far away must you be from a 675 kHz radio station with power 50.0 kW for there to be only one photon per second per square meter? Assume no reflections or absorption, as if you were in deep outer space. 2. Discuss the implications for detecting intelligent life in other solar systems by detecting their radio broadcasts.

Answers

Answer 1

a) 0.321 ly

b) 0.321 light years is not far in astronomical terms. Alien life would need to transmit at tremendous power in order for their radio transmissions to be detectable. Their radio signal also needs to be stronger than background noise in order to be distinguishable. Therefore it is unlikely that radio transmissions from alien life will ever be detected.


Related Questions

Jared walks 120 m east, 150 m south, and then 40 m west. Find the total
distance traveled by Jared

Answers

Answer:

310 m

Explanation:

120+150+40=310

A lightweight vertical spring of force constant k has its lower end mounted on a table. You compress the spring by a distance d, place a block of mass m on top of the compressed spring, and then release the block. The spring launches the block upward, and the block rises to a maximum height some distance above the now-relaxed spring. Find the speed of the block just as it loses contact with the spring.

Answers

Answer:

[tex]v=d\sqrt{\frac{k}{m}} [/tex]

Explanation:

In order to solve this problem, we can do an analysis of the energies involved in the system. Basically the addition of the initial potential energy of the spring and the kinetic energy of the mass should be the same as the addition of the final potential energy of the spring and the kinetic energy of the block. So we get the following equation:

[tex]U_{0}+K_{0}=U_{f}+K_{f}[/tex]

In this case, since the block is moving from rest, the initial kinetic energy is zero. When the block loses contact with the spring, the final potential energy of the spring will be zero, so the equation simplifies to:

[tex]U_{0}=K_{f}[/tex]

The initial potential energy of the spring is given by the equation:

[tex]U_{0}=\frac{1}{2}kd^{2}[/tex]

the Kinetic energy of the block is then given by the equation:

[tex]K_{f}=\frac{1}{2}mv_{f}^{2} [/tex]

so we can now set them both equal to each other, so we get:

[tex]=\frac{1}{2}kd^{2}=\frac{1}{2}mv_{f}^{2}[/tex]

This new equation can be simplified if we multiplied both sides of the equation by a 2, so we get:

[tex]kd^{2}=mv_{f}^{2}[/tex]

so now we can solve this for the final velocity, so we get:

[tex]v=d\sqrt{\frac{k}{m}} [/tex]

Find the net work done by friction on the body of a snake slithering in a complete circle of 3.93 m radius. The coefficient of friction between the ground and the snake is 0.25, and the snake's weight is 54.0 N.

Answers

Answer:

The net work done by friction on the body of the snake is 333.35J

Explanation:

Work done is given by

W = F × s

Where W is the Work done

F is the force

and s is the distance covered

Since we are to determine the work done by friction, then we will determine the frictional force. The frictional force is given by

f = μN = μw

Where μ is the coefficient of friction

N is the normal reaction

and w is the weight

But, F = f

∴ W = μws

From the question

μ = 0.25

w = 54.0 N

Now, we will determine s

From the question,

We are to determine the work done by friction on the body of a snake slithering in a complete circle of 3.93 m radius.

The distance s here is given by the circumference of the circle. Circumference of a circle is given by 2πr

∴ s = 2πr

s = 2 × π × 3.93

s = 7.86π m

Hence,

W = 0.25 × 54.0 × 7.86π

W = 333.35 J

Hence, the net work done by friction on the body of the snake is 333.35J.

The net work done by friction on the body of the snake is :

-333.35J

Friction

Formulas:

Work done (W) = F × s

F = force

s = distance covered

f = μN = μw

μ = coefficient of friction

N = normal reaction

w = weight

Solution:

F = f

Weight is :

W = μws

μ = 0.25

w = 54.0 N

Distance covered:

s = 2πr

s = 2 × π × 3.93

s = 7.86π m

Therefore,

W = 0.25 × 54.0 × 7.86π

W = 333.35 J

The net work done by friction on the body of the snake is 333.35J.

Learn more about "Friction":

https://brainly.com/question/13357196?referrer=searchResults

Suppose a cart with no fans has a starting velocity of 2 m/s. What will be the velocity of the cart when it reaches the wall?

Answers

Answer:

less than stating velocity due to friction and air resistance.

Explanation:



5.List the four goals of Psychology. Give your own example for each one using a behavior

Answers

Answer:

describe, explain, predict, and change/control behavior.

Explanation:

describe: What are they doing? -Pavlov noticed that dogs were salivating when they would see his lab assistant before food was presented to them. This observation acted as a description of what was happening to them.

explain: Why are they doing that?- Pavlov started to look into why they were doing it. There was a stimulus, the assistant giving them food in the past to where they started to salivate at the sight of the lab assistant

predict: What would happen if I responded in this way?- Pavlov predicted that he could get the same reaction if he used a bell as a stimulus. Using this he was able to condition dogs to salivate at the ring of the bell.

change/control: What can I do to get them to stop doing that? Because of this discovery we can use conditioning today. For example, in the classroom teachers can use conditioning with their students to make it easier, parents to teach their children right from wrong and to have good behavior. (you do this bad thing you get time out, do a good thing and I will praise you, etc) It can be used when training employees and many other places.

an object of mass 4kg moving with the initial velocity of 20m/s accelerates for 10s and attaind a final velocity of 60m/s calculate the initial momentum​

Answers

Explanation:

m = 4kg

u = 20m/s

t = 10s

v = 60m/s

initial momentum = mass × initial velocity

= 4 × 20 = 80kgm/s

On a double-well roller coaster, the person starts from a height of 10.5 meters, the height of the middle bump of the well is 6.7 meters. How much kinetic energy does this person have at the middle of the middle bump from the bottom if the mass of the person is 79 kg? (g=9.8 m/s2) Round to two decimal places.

Answers

Answer:

"2941.96 J" is the appropriate answer.

Explanation:

The given values are:

Mass,

m = 79 kg

Height,

h = 10.5 m

Now,

The total energy at the given height will be,

Potential energy = mgh

On substituting the values, we get

                                = [tex]79\times 9.8\times 10.5[/tex]

                                [tex]=8129.1 \ J[/tex]

So,

⇒ At height 6.7 m, total energy =  At height 10.5 m, total energy

On substituting the values, we get

⇒ [tex]Potential \ energy+Kinetic \ energy=8129.1[/tex]      

⇒       [tex]79\times 9.8\times 6.7+Kinetic \ energy=8129.1[/tex]

⇒                [tex]5187.14+Kinetic \ energy=8129.1[/tex]

⇒                                   [tex]K.E=8129.1-5187.14[/tex]

⇒                                   [tex]K.E=2941.96 \ J[/tex]

If the velocity of a car changes from 0 meters per second (m/s) to 100 m/s in 10 seconds, what is the acceleration over that 10 second period?

Answers

Answer:

10m/s²

Explanation:

Given parameters:

Initial velocity  = 0m/s

Final velocity  = 100m/s

Time taken  = 10s

Unknown:

Acceleration  = ?

Solution:

Acceleration is the rate of change of velocity with time.

  A = [tex]\frac{v - u}{t}[/tex]

v = final velocity

u = initial velocity

t = time taken

 So, insert the parameters and solve;

  A = [tex]\frac{100 - 0}{10}[/tex]   = 10m/s²

Which city did King David make the royal capital of the Kingdom of Israel?
Canaan
Jerusalem
Philistine
Cairo

Answers

Answer:

Jerusalem

Explanation:

because now a days jerusalem is the royal capital of the kingdom of israel so i conclude that the answer is jerusalem

A falling stone takes delta t = 0.32s to travel past a window 2.2m Tall. From what height above the top of the window did the stone fall?

Answers

Answer:

The height above the top of the window is 1.44 m

Explanation:

Given;

time of motion, t = 0.32 s

height traveled at the given time, h = 2.2m

determine the initial velocity of the stone;

h = ut + ¹/₂gt²

2.2 = u(0.32) + ¹/₂ x 9.8 x 0.32²

2.2 = 0.32u + 0.502

0.32u = 2.2 - 0.502

0.32u = 1.698

u = 1.698 / 0.32

u = 5.31 m/s

This initial velocity on top of the window becomes the final velocity from the height above the window.

v² = u² + 2gh

where;

u is the initial velocity of the stone from the height above the window;

5.31² = 0 + (2 x 9.8)h

19.6h = 28.196

h = 28.196/19.6

h = 1.44 m

Therefore, the height above the top of the window is 1.44 m

At which stage of the scientific process should a scientific look at experimental data from other scientists to set up a new experimental study

Answers

Answer:

Hypothesis

Explanation:

A 3520 kg truck moving north makes an INELASTIC collision with an 1480 kg car moving 13.0 m/s east. After colliding, they have a velocity of 9.80 m/s at 66.9 degrees. What was the initial velocity of the truck? (m/s)

Answers

Answer:

v = 12.8 m/s

Explanation:

Assuming no external forces acting during the collision, total momentum must be conserved.Since momentum is a vector, their components must be conserved too.Choosing a pair of axes coincident with the N-S and W-E directions, naming x to the W-E axis and y to the N-S one, we can write the following algebraic equations:      

       [tex]p_{ox} = p_{fx} (1)[/tex]

       [tex]p_{oy} = p_{fy} (2)[/tex]

Since we know all the information needed to solve (1), assuming a completely inelastic collision, we can focus in (2), writing both sides of the equation as follows:

       [tex]p_{oy} = m_{t} * v_{ot} = 3520 kg* v_{ot} (3)[/tex]

       [tex]p_{fy} = m_{f} * v_{fy} = 5000 kg* 9.8 m/s * sin 66.9 = 45080 kg*m/s (4)[/tex]

Since (4) and  (3) are equal each other, we can solve for vot, as follows:

       [tex]v_{ot} =\frac{45080kg*m/s}{3520kg} = 12.8 m/s (5)[/tex]

the resistance of a heater element is 1200 ohms and draws a circuit of 0.4 amperes calculate the voltage of the circuit​

Answers

Answer:

0.00033333333

Explanation:

24- What happens to a given mass of water as it is cooled from 4°C to zero?
(a) expands
(b) contracts
(c) vaporizes
(d) Neither expands, contracts, nor vaporizes.

Answers

Explanation:

A-It starts to expand. Hence ice and water of same weight has different volumes

Expansion happens to a given mass of water as it is cooled from 4°C to zero. Option A is correct.

What is temperature?

Temperature directs to the hotness or coldness of a body. In straightforward terms,

it is the method of finding the kinetic energy of particles within an entity. Faster the motion of particles more the temperature.

Water loses density when it is cooled from 4°C to 0°C. It turns out that the temperature at which liquid water has the most significant density is 4 degrees Celsius.

It will increase in size when heated or cooled. Since most liquids shrink when they are chilled, it is rare for water to expand when cooled to lower temperatures.

As a mass of water is cooled from 4°C to zero, expansion occurs.

Hence, option A is correct.

To learn more about the temperature refer to the link;

https://brainly.com/question/7510619

#SPJ2




You are standing on a circular track that is 332 m long. You begin jogging at the start line and keep jogging until you complete a full lap and stop at the same point you

started at.

ard

• What is your final displacement?

Answers

Answer:

Zero.

Explanation:

By definition, the displacement is the difference between the final position and the initial position, so independent from the distance traveled (in this case a full lap), since the initial and final position are the same, the net displacement is just Zero.

Need help ASAP..please help

Answers

Answer:

option 3

Explanation:

can i get brainliest

A string is waved up and down to create a wave pattern with a wavelength of 0.5 m. If the waves are generated with a frequency of 2 Hz, what is the speed of the wave that travels through the string to the other end? The speed of the wave is __ m/s.

Answers

Answer:

1m/s

Explanation:

Speed of a wave is expressed as;

Speed = frequency × wavelength

Given

Frequency = 2Hz

Wavelength = 0.5m

Required

Speed of the wave

Substitute

Speed = 2×0.5m

Speed = 1.0m/s

Hence the speed is 1.0m/s

How do the magnetic fields of Uranus and Neptune suggest that the mantles inside those planets are fluid?

Answers

Answer:

The surface must be a good absorber of light. Spectra of the planets proved that methane in the atmospheres of these planets is what absorbs red light.

Explanation:

A 4.5 kg puffer fish expands to 40% of its mass by taking in water. When the puffer fish is threatened, it releases the water toward the threat to move quickly forward. What is the ratio of the speed of the puffer fish forward to the speed of the expelled water backwards?

Answers

Answer:

2:5

Explanation:

We have the initial mass of the fish = 4.5kg

The mass of water intake = 40%of 4.5kg

= 0.40x4.5kg

= 1.8kg

The formula for conserving momentum

M1V1 = M2V2

M1 = mass of the puffer fish = 4.5kg

M2 = mass of the applied water = 1.8kg

V1 = velocity of the puffer fish

V2 = velocity of water

We are then to find v1/v2

V1/V2 = M2/M1

V1/V2 = 1.8/4.5

= 1/2.5

This is also 2/5

Therefore we have the ratio to be 2:5

A scientist decides to replicate an experiment completed by another scientist. Which statement describes something that would not affect the results of the replicated experiment

Answers

Hi, you've asked an incomplete question. However, I provided some explanation about the replication process that scientists do.

Explanation:

Replication in research involves carefully repeating an original experiment to see whether the same result would be arrived at as in previous research experiments.

For most scientists today, in other to avoid anything that would erroneously affect the results of the replicated experiment they usually follow the same procedures as carried by the previous researchers.

Is Geothermal Energy renewable? Why or why not? Use in your own words.

Answers

Yes, because it's from nature, sometimes nature renews it's sources.

Answer:

Yes, geothermal energy is a renewable energy resource because the water can be heated by pumping it through the rocks.

A typical sheet of printer paper is 8.5 inches wide and 11 inches long.
a.) Calculate the length of one sheet in cm
b.) Calculate the width of one sheet in cm?

Answers

Answer:

Explanation:

Given the length and width in inches

Length = 8.5in

Width = 11in

b) Convert to centimeters

1in = 2.54cm

8.5in = x

Cross multiply

x = 8.5 × 2.54

x = 21.59cm

Hence the width in cm is 21.59cm

a) 11in = y

1in = 2.54cm

Cross multiply

x = 11 × 2.54

x = 27.94cm

Hence the length in cm is 27.94cm

At high noon, the sun is almost directly above (about 2.0 degrees from the vertical) and a tall redwood tree casts a shadow that is 10m long. How tall is the redwood tree?

Answers

290m

The light always travels in a straight line.

At high noon, the ray from the sun is 2° from the vertical axis.

tan θ = (Opposite side)/(Adjacent side)

On applying above trigonometric formula, we get,

tan 2 = 10/h

0.035 = 10/h

∴ h = 10/0.035 = 290 m

A solid spherical ball and a hollow spherical ball made out of the same material are released from rest at the top of a ramp. They roll down the ramp without slipping to the bottom. On what quantities does the speed of each ball at the bottom of the ramp depend?A. Radius of the ball.B. Distribution of mass within the ball.C. Mass of the ball.D. Height of the ramp.

Answers

Answer:

D. Height of the ramp.

Explanation:

The solid spherical ball is expected to have more mass than that of the hollow spherical ball. And the speed of both balls would be influenced by the gravitational force as they roll down the ramp. Thus, the masses would move at different speed.

At the bottom of the ramp, the speed of the balls can be varied by varying the height of the ramp. So that the speed of both balls depend on the height of the ramp. As the height of the ramp increases, consequently, the speed of the balls increases. And if the height of the ramp decreases, the speed of the balls decreases consequently.

Astronauts on the first trip to Mars take along a pendulum that has a period on earth of 1.26 s. The period on the other planet turns out to be 3.82 s. What is the free-fall acceleration on that other planet?

Answers

Answer:

1.066 m/s^2

Explanation:

On the earth and on Mars respectively, the time periods of the pendulums are expressed as:

Tearth = 2pi * sqrt(L/gearth)

Tmars = 2pi * sqrt(L/gMars)

Divide the two equations above:

Tearth/Tmars = sqrt(gMars/gearth)

gMars = gearth(Tearth/Tmars)^2 = (9.80m/s^2)(1.26s/3.82s)^2 = 1.066 m/s^2

In Figure 1 , an engine that delivers power P is attached to a pulley that lifts a box of mass m0 a vertical distance of y0 at a constant speed in time t0 . If, as shown in Figure 2 the engine again delivers power P , how long would it take the engine to raise a box of mass 3m0 the same vertical distance y0 at a constant speed?

Options:
1/3 t0
t0
root(3 t0
3t0
9t0

Answers

Answer:

t = 3 t₀

Explanation:

The formula for the power delivered by the engine can be given in terms of the change in the potential energy of the box as follows:

P = P.E/t = mgy/t

where,

P = Power delivered by the engine

m = mass of box lifted = m₀

g = acceleration due to gravity

y = vertical distance or height box covered = y₀

t = time taken = t₀

Therefore,

P = m₀gy₀/t₀

t₀ = m₀gy₀/P   -------------- equation (1)

Now, if we change the mass of box as:

m = 3m₀

y = y₀ (constant)

P = Constant

Then,

P = 3m₀gy₀/t

t = 3m₀gy₀/P

using equation (1):

t = 3 t₀

Answer:

t=3to

Explanation:

I took the quiz it is right

A diffraction pattern is created on a screen when blue light is passed through a single slit. Does the central bright maximum in this pattern become wider or narrower, when the blue light is replaced by red light?

Answers

Answer:

becomes wider

Explanation:

From;   asin θ= m λ

It was said in the question that in this particular instance  blue light is replaced by red light. The wavelength of blue light is less than that of red light, it then follows that the central bright maximum in this pattern widens when red light is used.

Therefore the diffraction pattern becomes wider.

1. A spring extends by 10 cm when a mass of 100 g is attached to it. What is the spring constant? (Calculate your answer in N/m)10N/m



2. What will be the extension of this spring if the load is a) 4N and b) 75 g?

Answers

Answer:

1) k = 10 [N/m]

2) a-) x = 0.4 [m]

b)  x = 0.075 [m]

Explanation:

To be able to solve this type of problems that include springs we must use Hooke's law, which relates the force to the deformed length of the spring and in the same way to the spring coefficient.

F = k*x

where:

F = force [N] (units of Newtons]

k = spring constant  [N/m]

x = distance = 10 [cm] = 0.1 [m]

Now, the weight is equal to the product of the mass by the gravity

W = m*g = F

where:

m = mass = 100 [g] = 0.1 [kg]

g = gravity acceleration = 10 [m/s²]

F = 0.1*10 = 1 [N]

Now clearing k

k = F/x

k = 1/0.1

k = 10 [N/m]

2)

a ) if the force is 4 [N]

clearing x

x = F/k

x = 4/10

x = 0.4 [m]

m = 75 [g] = 0.075 [kg]

W = m*g = F

F = 0.075*10 = 0.75 [N]

x = .75/10

x = 0.075 [m]

A rock is thrown straight upward with a speed 6.000 m/s. If this rock takes 1.540 s to fall to the ground, from what height h was it released?

Answers

Answer:

3.8961038961038

Explanation:

6000/1540=3.8961038961038

X= v/t

A repeated back and forth or up and down motion is called a

Answers

Answer:

A vibration is a repeated back-and-forth or up-and-down motion.

Explanation:

Waves carry energy through empty space or through a medium without transporting matter.

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