this one too!! need just 1 answer about this system

Answer: Yes I am alive.

For a stationary siren on a firehouse is blaring at 81Hz. Assume the speed of sound to be 343m/s, the frequency perceived  is mathematically given as'

F=81.721Hz

Generally, the equation for the doppler effect  is mathematically given as

[tex]F'=\frac{vs+v}{vs}*f[/tex]

Therefore

F=81(343+3.05556)/343

F=81.721Hz

In conclusion, the frequency is

F=81.721Hz

Read more about frequency

https://brainly.com/question/24623209  

B

The combustion of the fuel in the helicopter is chemical energy. The vertical change in height is the result of kinetic energy. Because the helicopter is hovering in the air, it has gravitational potential.

Answer:

this would be B friend :)

Explanation:

Answer:

We stay hugely we devour

Explanation:

It's the rock

The stars which they should bet on is  D) a star of about 8% the mass of our Sun.

This refers to the astronomical object which is very far away in the galaxy and and of which the closest star to the Earth is in fact the Sun.

With this in mind, we can see that the students are making bets about the time different stars will take to evolve and want to know which star will become a red giant first so they should bet on a star of about 8% the mass of our Sun.

Read more about stars here:

https://brainly.com/question/25821071

Answer:

210m/s upwards

Explanation:

u= -30m /s

a= 120m/s^2

t=2s

v=u+at

=(-30)+(120x2)

=240-30

=210m/s

Answer:

Vacuum

Explanation:

Sound waves can travel through any medium, such as a solid, a liquid, or a gas. However, sound doesn’t travel through a vacuum, which is why sounds can't be heard in outer space.

PF

Since the magnetic flux through a coil of wire containing two loops changes at a constant rate from -58 wb to 38 wb in 0. 34 s, the emf induced in the coil is -5.65 V

The induced emf in the coil is given by ε = -NΔΦ/Δt where

Since ε = -NΔΦ/Δt

ε = -N(Φ₂ - Φ₁)/(t₂ - t₁)

Substituting the values of the variables into the equation, we have

ε = -N(Φ₂ - Φ₁)/(t₂ - t₁)

ε = -2(38 Wb - (-58 Wb))/(34 s - 0 s)

ε = -2(38 Wb + 58 Wb)/(34 s - 0 s)

ε = -2(96 Wb)/34 s

ε = -192 Wb/34 s

ε = -5.65 Wb/s

ε = -5.65 V

So, the emf induced in the coil is -5.65 V

Learn more about induced emf in coil here:

https://brainly.com/question/13051297

The electrical action generated by a non-electrical source, measured in volts. The emf induced in the coil is -564.7 V.

The electrical action generated by a non-electrical source, measured in volts, is referred to as emf or electromotive force. Devices, such as batteries or generators, generate an emf by converting various sources of energy into electrical energy.

The emf induced in a coil is given by

[tex]\varepsilon = \dfrac{-N \times \triangle \phi}{ \triangle t}[/tex]

where

ΔΦ is the change in magnetic flux, Δt is the change in time, and N is the number of loops.

Given that the initial magnetic flux is -58 Wb while the final magnetic flux is 38 Wb. Also, the change in time is 0.34 seconds and the number of loops is 2. Therefore, the emf induced can be written as,

[tex]\varepsilon = \dfrac{-N \times \triangle \phi}{ \triangle t}[/tex]

[tex]\varepsilon = \dfrac{-(2) \times [38-(-58)]}{0.34}\\\\\varepsilon = -564.7\rm\ V[/tex]

Hence, the emf induced in the coil is -564.7 V.

Learn more about EMF:

https://brainly.com/question/15121836

#SPJ4

Answer: 225 V

Explanation:

Given:

Secondary voltage,V2 = 150v

Resistance is connected across secondary winding,∴R2 = 20Ω

Supply current, ie, I1 = 5A

[tex]\text{Now, secondary current,} \ $I_{2}=\frac{V_{2}}{R_{2}}=\frac{150}{20}=7.5$$$\therefore I_{2}=7.5 \mathrm{~A}$$For Transformers, we have $\frac{N_{2}}{N_{1}}=\frac{V_{2}}{V_{1}}=\frac{I_{1}}{I_{2}}$ so, Taking $\frac{N_{2}}{N_{1}}=\frac{l_{1}}{l_{2}}$ inserting all given \& obtained values, we get $\frac{N_{2}}{N_{1}}=\frac{5}{7.5}$$$\therefore \text { Turns ratio }=\frac{N_{1}}{N_{2}}=\frac{7.5}{5}=\frac{3}{2}=3: 2$$[/tex]

[tex]\text{Again taking,}\frac{N_{1}}{N_{2}}=\frac{V_{2}}{V_{1}}$ \\So, \\$V_{1}=\frac{N_{1}}{N_{2}} V_{2}\\$ inserting all values, we get, $V_{1}=\frac{7.5}{5} * 150=225$\\Therefore, \fbox{Primary voltage, {$V_{1}=225 \mathrm{~V}$}}[/tex]

The direction of the normal contact force of the road on the wheels is : ( B ) Left

The contact force of the road on the wheels will act in a direction opposite to the movement of the wheel on the road. therefore as the wheel moves forward ( right ), the contact force will move backwards ( left ) of the direction of motion.

Hence we can conclude that the direction of the normal contact force of the road on the wheels is : ( B ) Left

Learn more about contact force : https://brainly.com/question/18451249

#SPJ2

Answer: hey here's your answer...

Explanation: We can think of a force as a push on a surface, such as the force due to gravity you exert when standing on a bathroom scale. Pressure involves the distribution of force. The scale measures force, not pressure, so your weight reading is the same no matter how you distribute your weight on the scale.

Hope this helps...

Have a nice day-

Answer:

One has 1E6 km^2 / MM

4E6 km^2 / (1E6 km^2/MM) = 4 MM or 4 megameter

In 4000,000 square kilometers, there are 4 square megameters if the one square megameter is equal to 1. 0×106 square kilometers.

It is defined as the conversion from one quantity unit to another quantity unit followed by the process of division, and multiplication by a conversion factor.

We have:

One square megameter = [tex]1\times10^6[/tex]

Let's suppose the x square megameters in the 4,000,000 square kilometers

Then x can be found as follows:

[tex]\rm x = \frac{4,000,000}{1\times10^6}[/tex]

x = 4 square megamters

Thus, in 4000,000 square kilometers, there are 4 square megameters if the one square megameter is equal to 1. 0×106 square kilometers.

Learn more about the unit conversion here:

brainly.com/question/14350438

#SPJ4

Answer:

To calculate the energy in joules, simply enter the mass of ammunition (in grams) that you use, and the fps that you've read from your Chrono unit.

The magnitude of the centripetal force on the car is 69.6 N.

This is a force acting on a body in circular path and it is directed to the center around which the body is moving.

To calculate the centripetal force on the car, we use the formula below.

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, the magnitude of the centripetal force on the car is 69.6 N.

Learn more about centripetal force here: https://brainly.com/question/20905151

Answer:

A

Explanation:

Think about rubbing your hands together- the friciton produces heat

The best answer is true. Yes, control rods are used to slow down the reaction in the reactor core when the core becomes too hot.

A nuclear reactor, often known as an atomic pile, is a device that initiates and controls nuclear chain reactions or nuclear fusion processes.

Nuclear reactors are used in nuclear power plants to generate energy as well as in nuclear marine propulsion.

Control rods are employed in nuclear reactors because the processes that occur in a nuclear reactor are very exothermic.

As a result, when these control rods are infused into a nuclear reactor, they absorb neutrons and aid in the management of the chain reaction. As a result, the rate of the chain reaction is brought under control.

As a result, we may infer that the statement control rods are employed to slow down the reaction in the reactor core when it gets too hot is correct.

Hence the best answer is true. Yes, control rods are used to slow down the reaction in the reactor core when the core becomes too hot.

To learn more about the nuclear reactor refer to the link;

https://brainly.com/question/896706

first we need omega

Hence

[tex]\\ \rm\rightarrowtail \omega=\dfrac{2\pi}{T}=2\pi[/tex]

Now

Total energy:-

[tex]\\ \rm\rightarrowtail \dfrac{1}{2}m\omega ^2A^2[/tex]

[tex]\\ \rm\rightarrowtail \dfrac{1}{2}(1)(2\pi)^2(1)^2[/tex]

[tex]\\ \rm\rightarrowtail \dfrac{1}{2}(4\pi ^2[/tex]

[tex]\\ \rm\rightarrowtail 2\pi ^2[/tex]

[tex]\\ \rm\rightarrowtail 2(3.14)^2[/tex]

[tex]\\ \rm\rightarrowtail 19.72J[/tex]

Answer:

An electron is a component of the broader term, electricity. Generally electricity refers to the control, manipulation, and use of the movement of electrons to perform some kind of work (motion/rotation, light, heat, etc…).

Explanation:

Or

put this

The study of electrons as it relates to their use in electric devices is electricity.

But I will go with the first one

Answer:

where is the displacement

[tex]v = \frac{s}{t} [/tex]

The average velocity of the fly between 0 and 15 seconds will be 10 m/sec.Velocity is the time-based component.

The average velocity is the ratio of the total distance traveled to the total time taken by the body. Its unit is m/sec.

From the given graph it is obsderved that the displacement from 0 to 15 seconds will be 150 m.

[tex]\rm V = \frac{D_2-d_1 }{t_2-t_1} \\\\ V = \frac{150}{15-0} \\\\ V= 10 \ m/sec[/tex]

Hence the average velocity of the fly between 0 and 15 seconds will be 10 m/sec.

To learn more about the average velocity refer to the link;

https://brainly.com/question/862972

#SPJ4

A decrease in production of goods could cause the economy to move from point a to point b.

Shifts in the production are due to  many factors that change the output of an economy such as advances in technology, changes in resources, more education or training and changes in the labor force.

So we can conclude that a decrease in production of goods could cause the economy to move from good to poor.

Learn more about economy here: https://brainly.com/question/17996535

The maximum value of the current depend on the frequency of the ac voltage source because it increases as the frequency increases.

The peak current of an ac source is the amplitude current flowing in the ac circuit.

The magnitude of the peak  current is calculated as follows;

I₀ = i/(sin ωt)

I₀ = i/(sin 2πft)

where;

i = I₀ x sin 2πft

From the equation above, as the frequency of the of the ac voltage source increases, the value of the ac current (i) increases.

Thus, the maximum value of the current depend on the frequency of the ac voltage source because it increases as the frequency increases.

Learn more about ac current here:  https://brainly.com/question/10715323

#SPJ1

Answer:

buying and selling goods and services. and exchange account

Explanation:

:)

Answer:

when money is used to intermediate the exchange of goods and services

Answer:

Gravitational tugs from orbiting planets don't affect the motion of a star. The star, being much larger than the planet, has a much smaller orbit. But it does move slightly. Explain how alien astronomers could deduce the existence of planets in our solar system by observing the Sun's motion.

By the work-energy theorem, the block's kinetic energy is increased by 15 J. The only force performing work on the block is the constant 5.0-N push.

Answer:

(c) the male vocal cord is longer

Explanation:

Males have a lower pitch in their voises than females, elongating men's vocal cords.

I am joyous to assist you at any time.

Voice of man is heavy compared to a woman because male vocal cord is longer.

The change is caused by an enlargement in the vocal folds, generating a more serious and adult voice. Generally speaking, the male voice is deeper than the female voice because the vocal muscles grow more in men than in women.

Males have a lower pitch in their voises than females, elongating men's vocal cords.

See more about vocals at brainly.com/question/13932020

#SPJ5

Answer:

what are you calculating put the full question so I can help you out: )

Explanation:

its quite confusing just a little lol