William B. Hartsfield was a man of humble origins who became one of the greatest mayors of Atlanta. He served as mayor for six terms (1937–41, 1942–61), longer than any other person in the city's history. Hartsfield held office during a critical period when the color line separating the races began to change and the city grew . . . to a metropolitan population of one million. He is credited with developing Atlanta into the aviation powerhouse that it is today . . . . . . . On August 30, 1961, the city peacefully integrated its public schools. As a result, Atlanta began to acquire its reputation as "A City Too Busy to Hate."

–New Georgia Encyclopedia

During Hartsfield’s time in office, Atlanta became known as "A City Too Busy to Hate.” What factors supported this nickname? Check all that apply.

The city integrated its schools.
Atlanta became a leader in aviation.
The economy declined.
The population increased to one million.
Many people served as the city mayor.

The watt is a rate, similar to something like speed (miles per hour) and other time-interval related measurements.

Specifically, watt means Joules per Second. We are given that the electrical engine has 400 watts, meaning it can make 400 joules per second. If we need 300 kJ, or 3000 Joules, then we can write an equation to solve the time it would take to reach this amount of joules:

w * t = E

w: Watts

t: Time

E: Energy required

(Watts times time is equal to the energy required)

Input our values:

400 * t = 3000

(We need to write 3000 joules instead of 300 kilojoules, since Watts is in joules per second. It's important to make sure your units are consistent in your equations)

Divide both sides by 400 to isolate t:

[tex]\frac{400t}{400}[/tex] = [tex]\frac{3000}{400}[/tex]

t = 7.5 (s)

It will take 7.5 seconds for the 400 W engine to produce 300 kJ of work.

If you have any questions on how I got to the answer, just ask!

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The 400 W electrical engine must work for 12 minute 30 second in order to produce 300 kJ of work.

The quantity of energy moved or converted per unit of time is known as power in physics. The watt, or one joule per second, is the unit of power in the International System of Units. Power is also referred to as activity in ancient writings. A scalar quantity is power.

Power of the electrical engine = 400 Watt.

Work done by the electrical energy = 300 kJ

= 300 × 1000 Joule

= 300000 Joule.

Now from the definition of power:

Power = Work done/time interval

Hence, required time interval = work done/ power

= 300000 Joule/400 watt

= 750 second

= 12 minute 30 second.

Hence,  a 400 W electrical engine must work for 12 minute 30 second in order to produce 300 kJ of work.

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Answer:

let say it will be positive

Answer:

Mass doubles

Explanation:

Since F = ma, and given that the acceleration stayed constant, the mass must have changed. (Assuming thatt when the problem states the force doubles, they mean the net force doubles). Note, that the mass does not have to change if the acceleration is zero.

Answer: i may not be 100% accurate but i believe it is iron, there is a fire work that uses iron to shine a certain way and is found on stars.

Answer:

The magnitude of the force per unit length is 2.145 x 10⁻⁵ N/m and the direction of the force is outward or repulsive since the current in the two parallel wires are flowing in opposite direction.

Explanation:

Given;

distance between the parallel wires, r = 5.0 cm = 0.05 m

current in the first wire, I₁ = 1.65 A

current in the second wire, I₂ = 3.25 A

The magnitude of the force per unit length between the two wires is calculated as follows;

[tex]\frac{F}{l} =\frac{\mu_0 I_1 I_2}{2\pi r} \\\\\frac{F}{l} =\frac{4\pi \times 10^{-7} \times 1.65 \times 3.25}{2\pi \times 0.05} \\\\\frac{F}{l} = 2.145 \times 10^{-5} \ N/m[/tex]

Therefore, the magnitude of the force per unit length is 2.145 x 10⁻⁵ N/m and the direction of the force is outward or repulsive since the current in the two parallel wires are flowing in opposite direction.

Answer:

1) Van der rcf generator

2) the charge is distributed among all the hairs, as they all have the same potential,

the charges are of the same sign repel each other

Explanation:

1.) The object is a Van der rcf generator, which is loaded by friction,

The girl has no load

2) when the girl touches the sphere of the generator part of the electrons of this is transferred to the girl, when this charge reaches the hair, the charge is distributed among all the hairs, as they all have the same potential,

the charges are of the same sign repel each other

Answer:

b. He is 8 years old

Explanation:

We will use Einstein's formula for time dilation, to calculate the age of Lee. Because Lee was traveling comparable to the speed of light, his age must be lesser than Leigh.

[tex]T = \frac{T_o}{\sqrt{1-\frac{v^2}{c^2} } }[/tex]

where,

T₀ = Time on Earth = ?

T = Relative Time = 10 years

v = relativistic speed of Lee = 0.714 c

c = speed of light = 3 x 10⁸ m/s

Therefore,

[tex]10\ years = \frac{T_o}{\sqrt{1-\frac{(0.714\ c)^2}{c^2} } } \\\\[/tex]

T₀ = 7 years

Hence, the age of Lee will be:

[tex]Lee's\ Age = 1\ year + 7\ years = 8\ years[/tex]

b. He is 8 years old

Answer:

T₂ = 16.83°C

Explanation:

Applying the law of conservation of energy principle here in this situation we get the following equation:

[tex]Energy\ Lost\ by\ Metal = Energy\ Gaine\ by\ Water\\m_{metal}C_{metal}(T_2-T_{1metal}) = m_{w}C_{w}(T_2-T_{1w})[/tex]

where,

T₂ = Final Temperature of Water = Final Temperature of Metal = ?

C_metal = Specififc Heat Capacity of the metal = 2.11 x 10² J/lg.°C

T_1metal = Initial Temperature of Metal = 225°C

m_metal = mass of metal = 1 x 10⁻²[tex](0.01\ kg)(211\ J/kg.^oC)(T_2-225^oC) = (0.09\ kg)(4184\ J/kg.^oC)(T_2-18^oC)\\2.11 T_2 - 474.75 = 376.56T_2 - 6778.08\\374.45T_2 = 6303.33\\[/tex] kg (exponent assumed due to missing info in question)

C_w = Specififc Heat Capacity of the water = 4184 J/lg.°C

T_1w = Initial Temperature of water = 18°C

m_w = mass of water = 0.09 kg

Therefore,

[tex](0.01\ kg)(211\ J/kg.^oC)(T_2-225^oC)=(0.09\ kg)(4184\ J/kg.^oC)(T_2-18^oC)\\\\2.11 - 474.75T_2 = 376.56 - 6778.08T_2\\[/tex]

T₂ = 16.83°C

Answer:

If you are at sea level, each square inch of your surface is subjected to a force of 14.6 pounds. The pressure increases about one atmosphere for every 10 meters of water depth. At a depth of 5,000 meters the pressure will be approximately 500 atmospheres or 500 times greater than the pressure at sea level.

Explanation:

At sea level, a force of 14.6 pounds is applied to every square inch of your surface. For every 10 meters of sea depth, the pressure rises by approximately one atmosphere. The pressure will be about 500 atmospheres, or 500 times more than the pressure at sea level, at a depth of 5,000 meters.

Pressure is defined as the force applied perpendicularly to an object's surface divided by the surface area over which it is applied.

Pressure is the physical amount of force exerted on a particular area.

Pressure can be expressed as

Pressure = Force / area

There are three types  of pressure.

Thus, at sea level, a force of 14.6 pounds is applied to every square inch of your surface. For every 10 meters of sea depth, the pressure rises by approximately one atmosphere. The pressure will be about 500 atmospheres, or 500 times more than the pressure at sea level, at a depth of 5,000 meters.

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Answer:

[tex]d=5\ g/cm^3[/tex]

Explanation:

Given that,

Mass of the object, m = 100 grams

Volume of the object, V = 20 cm³

We need to find the density of the object. We know that, density is equal to mass per unit volume. So,

[tex]d=\dfrac{m}{V}\\\\d=\dfrac{100\ g}{20\ cm^3}\\\\d=5\ g/cm^3[/tex]

So, the density of the object is equal to [tex]5\ g/cm^3[/tex].

Answer:

When we have a current I, we will have a magnetic field perpendicular to this current.

Then if we have a wire in a "spring" form. then we will have a magnetic field along the center of this "spring".

Now suppose we put an iron object in the middle (where the magnetic field is) then we will magnetize the iron object.

Of course, the intensity of the magnetic field is proportional to the current, given by:

B = (μ*I)/(2*π*r)

Where:

μ is a constant, I is the current and r is the distance between to the current.

Now remember that for a resistor:

R = ρ*L/A

R is the resistance, ρ is the resistivity, which depends on the material of the wire, L is the length of the wire, and A is the cross-section of the wire.

If we increase the area of the wire (if we use a thicker wire).

And the relation between resistance and current is:

I = V/R

Where V is the voltaje.

Now, if we use a thicker wire, then the cross-section area of the wire increases.

Notice in the resistance equation, that the cross-section area is on the denominator, then if we increase the area A, the resistance decreases.

And the resistance is on the denominator of the current equation, then if we decrease R, the current increases.

If the current increases, the magnetic field increases, which means that we will have a stronger electromagnet.

Answer:

The kinetic energy of large objects can be converted into this thermal energy.

Explanation:

For example, if you drop a water balloon onto the ground, its kinetic energy is converted mostly to thermal energy. If the balloon weighs 1 kilogram and you drop it from about 2 meters, it will heat up by less.

Answer: c is correct

Explanation: i did this

Answer:

Drinking straw, syringe, Dropper, vacuum, etc.

Explanation:

Answer:

A ray of light is incident from air on the surface of a block of clear ice (nice=1.31) at an angle of 45.0° with the normal. Part of the light is reflected and part is refracted. Find the angle between the reflected and refracted light.

Answer: I like your profile picture

Explanation:

Answer:

srghgddggjjjkkkk

Explanation:

fhhgxxxxxxxx3

errghydhi

Answer:

true  b, e

Explanation:

The expression that describes the diffraction of a grating is

         d sin θ = m λ

where d is the separation between the slits, m is the order of the spectrum

let's analyze the different answers

a) False. The size (height) of the slits does not influence the resolution, the number of them per unit of length influences, the greater the number, the smaller the distance (d) this they

b) True. The spectrum is resolved on a screen, in the form that each wavelength corresponds to a fixed distance from the central maximum, for a given order

c) False. The exit slit selects a given wavelength, but does not deflect the beam from its path

d) False. The slit lets in light, but does not measure its intensity

e) True. For a continuous spectrum, the wavelength variation that passes through a slit is proportional to its width. For a discrete spectrum the width of the slit does not affect the wavelength

Answer:

10 N

Explanation:

Given that,

Force applied by a person = 25 N

Force of friction = 15 N

The net force acting on the box is given by :

F = Applied force - the force of friction

So,

F = 25 N - 15 N

F = 10 N

So, the required force is equal to 10 N.

Answer:

The velocity and translational kinetic energy of the acorn when hitting the ground are approximately 19 meters per second and 3 joules, respectively.

Explanation:

Let suppose that the acorn is a conservative system. By Principle of Energy Conservation, we understand that initial potential gravitational potential energy ([tex]U_{g}[/tex]), in joules, which is related to initial height above the ground, is equal to the final translational kinetic energy ([tex]K[/tex]), in joules, related to the instant just before hitting the ground. Let suppose that ground has a height of zero. That is:

[tex]U_{g} = K[/tex] (1)

[tex]m\cdot g \cdot h = \frac{1}{2}\cdot m \cdot v^{2}[/tex] (1b)

Where:

[tex]m[/tex] - Mass, in kilograms.

[tex]g[/tex] - Gravitational acceleration, in meters per square second.

[tex]h[/tex] - Height, in meters.

[tex]v[/tex] - Speed, in meters per second.

If we know that [tex]m = 0.017\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]h = 18.5\,m[/tex], then the velocity and the translational kinetic energy of the acorn just before hitting the ground is:

[tex]m\cdot g \cdot h = \frac{1}{2}\cdot m \cdot v^{2}[/tex]

[tex]v = \sqrt{2\cdot g \cdot h}[/tex]

[tex]v \approx 19.049\,\frac{m}{s}[/tex]

[tex]K = \frac{1}{2}\cdot m\cdot v^{2}[/tex]

[tex]K = 3.084\,J[/tex]

The velocity and translational kinetic energy of the acorn when hitting the ground are approximately 19 meters per second and 3 joules, respectively.

Answer:

Newton's law of cooling states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings. The law is frequently qualified to include the condition that the temperature difference is small and the nature of heat transfer mechanism remains the same. As such, it is equivalent to a statement that the heat transfer coefficient, which mediates between heat losses and temperature differences, is a constant. This condition is generally met in heat conduction (where it is guaranteed by Fourier's law) as the thermal conductivity of most materials is only weakly dependent on temperature. In convective heat transfer, Newton's Law is followed for forced air or pumped fluid cooling, where the properties of the fluid do not vary strongly with temperature, but it is only approximately true for buoyancy-driven convection, where the velocity of the flow increases with temperature difference. Finally, in the case of heat transfer by thermal radiation, Newton's law of cooling holds only for very small temperature differences.

When stated in terms of temperature differences, Newton's law (with several further simplifying assumptions, such as a low Biot number and a temperature-independent heat capacity) results in a simple differential equation expressing temperature-difference as a function of time. The solution to that equation describes an exponential decrease of temperature-difference over time. This characteristic decay of the temperature-difference is also associated with Newton's law of cooling

Answer:fuafnshf dj en jz

Explanation:

Can. Nd I do j dj cdj an man Jaz jxn nah an b

Answer:

The potential difference between the ends of a wire is 60 volts.

Explanation:

It is given that,

Resistance, R = 5 ohms

Charge, q = 720 C

Time, t = 1 min = 60 s

We know that the charge flowing per unit charge is called current in the circuit. It is given by :

I = 12 A

Let V is the potential difference between the ends of a wire. It can be calculated using Ohm's law as :

V = IR

V = 60 Volts

So, the potential difference between the ends of a wire is 60 volts. Hence, this is the required solution.

Answer:

We can conclude by saying that in the beginning current will increase but after sometime, it becomes saturated.

Explanation:

Note: No information on change in number of electron generated.

Since there is a collision, the electrons emitted will not reach the collector at same time. As the voltage is increased, the the speed with which the electrons will reach the collector starts to increase. Due to this, electric current will first increases till all the emitted electrons reach the collector. Since we are not provided with the information that number of electrons generated are changing, after increasing voltage current will increase for some time and then reaches a saturated state.

We can conclude by saying that in the beginning current will increase but after sometime it becomes saturated.

Answer:

The Earth's magnetic field intensity is roughly between 25,000 - 65,000 nT (.25 -.65 gauss).

Explanation:

To measure the Earth's magnetism in any place, we must measure the direction and intensity of the field. The Earth's magnetic field is described by seven parameters. These are declination (D), inclination (I), horizontal intensity (H), the north (X), and east (Y) components of the horizontal intensity, vertical intensity (Z), and total intensity (F). The parameters describing the direction of the magnetic field are declination (D) and inclination (I). D and I are measured in units of degrees, positive east for D and positive down for me. The intensity of the total field (F) is described by the horizontal component (H), vertical component (Z), and the north (X) and east (Y) components of the horizontal intensity. These components may be measured in units of gauss but are generally reported in nanoTesla (1nT * 100,000 = 1 gauss). The Earth's magnetic field intensity is roughly between 25,000 - 65,000 nT (.25 - .65 gauss). Magnetic declination is the angle between magnetic north and true north. D is considered positive when the angle measured is east of true north and negative when west.  The magnetic inclination is the angle between the horizontal plane and the total field vector, measured positive into Earth. In older literature, the term “magnetic elements” is often referred to as D, I, and H.

Answer:

0 290

Explanation:

Answer:

290

Explanation:

the reason is that the formula for kinetic energy is half m×v².

you divde half by 0.30 multiply by 44×44

you get 290.4

then you round it to significant figures to get 290

Answer:

Homogeneous mixtures

Explanation:

I think so because homogeneous means mixed mixtures