Answer:
Approximately [tex]5.11 \times 10^{-19}\; {\rm J}[/tex].
Explanation:
Since the result needs to be accurate to three significant figures, keep at least four significant figures in the calculations.
Look up the Rydberg constant for hydrogen: [tex]R_{\text{H}} \approx 1.0968\times 10^{7}\; {\rm m^{-1}[/tex].
Look up the speed of light in vacuum: [tex]c \approx 2.9979 \times 10^{8}\; {\rm m \cdot s^{-1}}[/tex].
Look up Planck's constant: [tex]h \approx 6.6261 \times 10^{-34}\; {\rm J \cdot s}[/tex].
Apply the Rydberg formula to find the wavelength [tex]\lambda[/tex] (in vacuum) of the photon in question:
[tex]\begin{aligned}\frac{1}{\lambda} &= R_{\text{H}} \, \left(\frac{1}{{n_{1}}^{2}} - \frac{1}{{n_{2}}^{2}}\right)\end{aligned}[/tex].
The frequency of that photon would be:
[tex]\begin{aligned}f &= \frac{c}{\lambda}\end{aligned}[/tex].
Combine this expression with the Rydberg formula to find the frequency of this photon:
[tex]\begin{aligned}f &= \frac{c}{\lambda} \\ &= c\, \left(\frac{1}{\lambda}\right) \\ &= c\, \left(R_{\text{H}}\, \left(\frac{1}{{n_{1}}^{2}} - \frac{1}{{n_{2}}^{2}}\right)\right) \\ &\approx (2.9979 \times 10^{8}\; {\rm m \cdot s^{-1}}) \\ &\quad \times (1.0968 \times 10^{7}\; {\rm m^{-1}}) \times \left(\frac{1}{2^{2}} - \frac{1}{8^{2}}\right)\\ &\approx 7.7065 \times 10^{14}\; {\rm s^{-1}} \end{aligned}[/tex].
Apply the Einstein-Planck equation to find the energy of this photon:
[tex]\begin{aligned}E &= h\, f \\ &\approx (6.6261 \times 10^{-34}\; {\rm J \cdot s}) \times (7.7065 \times 10^{14}\; {\rm s^{-1}) \\ &\approx 5.11 \times 10^{-19}\; {\rm J}\end{aligned}[/tex].
(Rounded to three significant figures.)
Find the heat given off if 1 kg of 125 degree C steam is cooled to 50 degree C water.
[tex]\\ \sf{:}\Rrightarrow Q=mc\Delta T[/tex]
[tex]\\ \sf{:}\Rrightarrow Q=1(4184)(75)[/tex]
[tex]\\ \sf{:}\Rrightarrow Q=313800J[/tex]
[tex]\\ \sf{:}\Rrightarrow Q=313.8KJ[/tex]
you serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 30 m/s. The ball has how much energy
Answer:
In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.
What is Newton's 1st Law?
Forces come in pairs that are equal in size and opposite in direction.
F=ma
An object in motion will stay in motion at the same speed and in the same direction (ie with constant velocity) unless a force makes it change.
Answer:
An object in motion will stay in motion at the same speed and in the same direction (ie with constant velocity) unless a force makes it change.
Explanation:
Draw the following vector: 350 N, 30° south of east [1 cm = 50 N]
The magnitude and the position of the 350 N vector can be represented using arrow pointing out from the South-East of a Cartesian coordinate.
The given parameters:
Magnitude of the vector = 350 NPosition of the vector = 30⁰ South eastThe vector is represented with arrow pointing out from south-east represented in a Cartesian coordinate.
The length of the arrow represents the magnitude of the vector which is 350 N. The direction of the arrow indicated by the arrow head represents the position of the vector.The position of the vector is 30 degrees South of East.Thus, the magnitude and the position of the 350 N vector can be represented using arrow pointing out from the South-East of a Cartesian coordinate.
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why efficiency of energy converters is less than 100%
The output work is always less than the input work because some of the input work is used to overcome friction.
Determine the kinetic energy of a 1500 kg roller coaster that is moving with a
speed of 35 m/s.
A) 200,000 J
B) 25,000
C) O 918,750
D) 920,000J
Answer:
918,750 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass in kg
v is the velocity in m/s
From the question
m = 1500 kg
v = 35 m/s
We have
[tex]k = \frac{1}{2} \times 1500 \times {35}^{2} \\ = 750 \times 1225 \\ = 918750[/tex]
We have the final answer as
918,750 JHope this helps you
describe how visible light is used with solar photovoltaic panels to produce electricity
Photovoltaic panels are used to produce alternating current using sunlight. It uses solar cells which are photoactive and produce a photoelectric effect and thereby a potential is created.
What is photoelectric effect?When photons from the light energy is hit on a metallic surface the photon collides with the electrons of the metals and electrons are ejected from the metal surface. This phenomenon is called photoelectric effect.
In a solar photovoltaic panel, photovoltaic cells layers of semi-conducting materials, such as silicon, are sandwiched photovoltaic cells. When photons from sunshine strike each layer, its unique electronic properties energise and produce an electric field.
The current required to generate electricity is produced through what is known as the photoelectric effect. Electricity produced by solar panels is in the direct current form. This is then transformed into an alternating current by passing via an inverter.
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[URGENT] A swimmer wants to end up at a dock due north of her starting position on the south shore of a river. In still water her maximum speed is 1.25m/s. The river has a current flowing 0.35m/s [E].
a.) calculate the direction that she must aim herself through the water to arrive at the dock.
b.) how long will it take for the swimmer to cross the river, if the distance from the starting point to the dock is 300 m?
Please show all your work, thanks
Explanation:
As you can see in the picture, we want the swimmer to go on a straight line, so the speed of the water must be equal to the speed of the swimmer along the x-axis. We also know the value of v, so we can calculate the of the cosine of the angle (alpha) between Vx and V. Thanks to the fundamental relation of gioniometry (cos^2(x) + sin^2(x) = 1) we can find the sine of alpha and calculate Vy. With Vy we can calculate the time that the swimmer will use for reaching the dock: s = Vy * t => t = s/(Vy).
I'll let you do all the calculations, you just have to plug in values.
a)The direction that she must aim herself through the water to arrive at the dock will be 73.7°.
b)The time it takes for the swimmer to cross the river will be 240 seconds.
What is speed?Speed is defined as the rate of change of the distance or the height attained. it is a time-based quantity. it is denoted by u for the initial speed while v for the final speed. its si unit is m/sec.
Given data;
The maximum speed of the swimmer In still water,v=1.25m/s.
Speed of river = 0.35m/s [E]
α is the direction that she must aim herself through the water to arrive at the dock.
t is the time it takes for the swimmer to cross the river
The distance from the starting point to the dock is,s = 300 m
If the swimmer were to swim straight, the water's speed along the x-axis would have to match that of the swimmer.
[tex]\rm v_w = v_x = 0.35 \ m/sec[/tex]
α is the angle between vx and v
The value of the
[tex]\rm cos \alpha = \frac{v_x}{v} \\\\ \alpha = cos ^{-1}(\frac{0.35}{1.25} )\\\\ \alpha = 73.7 ^0[/tex]
The time that the swimmer will use for reaching the dock;
s = V×t
t = s/(v)
t=300 m / 1.25 m/sec
t = 240 seconds
Hence, the direction that she must aim herself through the water to arrive at the dock. and it takes for the swimmer to cross the river will be 73.7° and 240 seconds respectively.
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A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able
to slide past each other.
What is most likely the phase of the substance?
gas
o liquid
O solid
anggas
liquid and solid
Help
Me please I search this and there was only an asian answer
Answer:
A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. The most likely phase of the substance is liquid.
A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. What is most likely the phase of the substance?
gas. NO. Gases have expansibility, that is, they occupy all the space available, so they wouldn't occupy just one half of the container.
liquid. YES. The description fits the liquid phase.
solid and gas. NO. Solids occupy fixed positions and their atoms can't slide past each other.
liquid and solid. NO. Solids can't be present due to their lack of movement.
A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other. The most likely phase of the substance is liquid.
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Explanation:
why does rhododendron not grow well in the terai region of nepal give reason
Answer:
Tge Rhododendrob is the national flower of Nepal. The hills and mountain sides ranges of Nepal are decorated with diff colours and shapes
practical examples of radition
Describe the relative energies of particles in the
different States of matter.
Answer:
MATTER
ARE
OF
THREE
TYPES
SOLID
LIQUID
GAS
A truck is parked outside. When the sun goes down, the temperature
outside decreases. What will happen to the volume of the gas inside of the
tires during the night ?
Answer:
Colder.
When the temperature is high, the air in your tires takes up more volume, where as when the temperature is cold, the air takes up less volume.
The air in your tires expands more in hot weather and contracts more in cold weather, depending on the temperature.
What is Temperature?A temperature is a unit of hotness or coldness that can be described in terms of a variety of arbitrary scales. It also indicates the direction in which heat energy will naturally flow, i.e., from a hotter body to something like a colder body.
Heat is not the same as the power of a heat engine; for instance, an iceberg has a considerably higher temp than a blazing match, but it has a far larger total thermal energy than a match.
As opposed to extensive qualities like mass or volume, which are reliant on the amount of stuff being studied, the temperature is indeed an intensive attribute, just like pressure and density.
When the temperature will decrease then the molecules get compact or come close to each other due to which the reduction in the volume will take place.
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A 1,500 kg car is traveling at 25 m/s. The driver suddenly applies the brakes causing the car to skids to a stop. If the average braking force between the tires and the road is 7,100 N, how far does the car slide before it comes to rest?
By Newton's second law, the car slows down with an average acceleration a such that
-7100 N = (1500 kg) a ⇒ a ≈ -4.7 m/s²
If we treat the car as accelerating uniformly with this magnitude, then the car slides a distance ∆x such that
0² - (25 m/s)² = 2a ∆x ⇒ ∆x ≈ 66 m
The car slide before it comes to rest will be 66 m. Newton's second equation of motion is applied in this problem.
What is force?Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
Force is defined as the product of mass and acceleration. Its unit is Newton.
The acceleration is found as;
F=ma
-7100 N = (1500 kg) a
a= -4.7 m/s²
If we assume that the automobile accelerates uniformly with this magnitude, the car slides x distance. From the Newton's second equation of motion;
v²=u²+2as
v²-u²=2as
0² - (25 m/s)² =2×(-4.7) s
s=66 m
Hence,the car slide before it comes to rest will be 66 m.
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PLEASE HELP LIKE AN ACUALL ANSWER NOT SPAM NO ONE IS GUNNA CLICK THE LINK
Answer:
C. 9.8
Explanation:
light of wavelength 633 nm from a distant source is incident on a slit 0.750 mm wide, and the resulting diffraction pattern is observed on a screen 3.50 m away.
Answer:
because of the gravity of the earth
If you are soaking wet and the water on your clothes evaporates, you will feel cold. Explain the cooling effect in the terms of kinetic theory.
Evaporation is a type of vaporization which usually occurs in liquid when molecules of that liquid transform into the gaseous phase.
Evaporation causes cooling. This is because, when a molecule wants to evaporate, it requires heat to do so.
This heat is derived from the surface from which the molecule is about to evaporate. The emission of heat from this surface results in the cooling of the surface left behind.
Kinetic Theory and Evaporation.Liquid molecules are in constant random motion while possessing different velocities.
Molecules which are near the surface possess higher velocities and kinetic energy escape from the surface.
Since the average kinetic energy is a measure of temperature, it implies that the temperature is lowered and hence a person who is soaking wet feels cold when evaporation occurs.
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A man pushes a box with a force of 75N across a 12M loading dock. How much work did he do on the box?
Once again, Have a Happy, Merry Christmas!! =)
Answer: 75n,a * (12m)
Explanation I'm trying to understand the question but this is what i got.
Happy Holidays!
We can use the following equation to calculate work done on an object.
W = F · d
Work (J) = Force (N) · displacement (m)
Plug in the given values into the equation:
W = 75 · 12 = 900 J
Name a device or gadget that converts
a) Heat energy to mechanical energy b) heat energy to light energy
c)electrical energy to sound energy
Answer:
a heat engine converts heat to mechanical energy.
electric generator
what's some examples of inertial reference frames?
Answer:
Isolated spaceship, far, far away from the Earth, the Sun, the Milky Way Galaxy, and all other massive objects.
Explanation:
if the spring balance with the iron ball is relaesed what reading will the spring balance record and wht
Answer:
when it is released the reading will be zero because gravitational force acts on it you can also say as free fall body
Explanation:
Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill?
a
Kinetic energy decreases and potential energy increases.
b
Both potential energy and kinetic energy decrease.
c
Both potential energy and kinetic energy increase.
d
Kinetic energy increases and potential energy decreases.
Answer: When a child is riding on a sled down a steep, snow-covered hill, his elevation decreases and hence Kinetic energy increases and potential energy decreases.
i think this will help you
explain why an astronaut on moon seems to be attracted only to the moon
Answer: the gravitational attraction on the Moon is much less than it is here on Earth, and a person weighs less on the Moon.
Explanation:
John does 3.2J of work to lower the window shade in her bedroom a distance of 0.8m. How much force must John exert on the window shade?
Answer:
[tex]\boxed {\boxed {\sf 4 \ Newtons}}}[/tex]
Explanation:
Work is energy transferred when an object is moved. It is the product of force and distance.
[tex]W= F*d[/tex]
John did 3.2 Joules of work or 3.2 Newton meters of work (the units are equivalent). The window shade was lowered a distance of 0.8 meters.
W=3.2 N*m d= 0.8 mSubstitute the values into the formula.
[tex]3.2 \ N *m = F * 0.8 \ m[/tex]
We are solving for the force, so we must isolate the variable F. It is being multiplied by 0.8 meters. The inverse operation of multiplication is division, so divide both sides of the equation by 0.8 m.
[tex]\frac {3.2 \ N*m}{0.8 \ m}= \frac{ F* 0.8 \ m}{0.8 \ m}[/tex]
The units of meters cancel.
[tex]\frac {3.2 \ N}{0.8 }=F[/tex]
[tex]4 \ N = F[/tex]
John must exert 4 Newtons of force.
What is the speed of an 800 kg automobile if it has a kinetic energy of 9.00 x 10^J?
Ek = 1/2 mv^2
9 × 10^4 = 1/2 × 800 × v^2
9 × 10^4/400 = 400 v^2 / 400
9 × 10^4/400 = v^2
√225 = v
15 ms⁻¹ = v
That's the only way I know how to work it out
I think in this case velocity and speed would be considered the same because me
s = d/t and v=d/t
one is distance travelled and the other is displacement of a body
Which source of evidence did Wegener use to support his theory of continental drift?
fossils found on Earth
magnetic fields of Earth
satellite mapping of the tropical islands
glaciers found near the poles
Answer:
fossils found on Earth
Explanation:
i just did the test 100%
Answer:
Fossils on Earth
Explanation:
Fossils can show that the continents were all together by putting them together on a map you can see the fit. and when you look where fossils were, they would be right next to each other.
the smallest division value of electronic balance
Answer:
0.1g to 0.0000001g hope it helps uu
Please please help
Matter is made up of particles which
are too small to see without the aid of
a microscope. What do scientists call
these particles?
A.bonds
B.mixtures
C.energy
D.atoms
Answer:
D
Explanation:
[Ans. 2000 kg /m] f. If the mass of a substance having its volume 80 cm is 68 g. Calculate the density of the substance. Ans. 0.85 g/cm3]
Answer:
The density of the substance is
[tex]0.85\: \: g \: \: \: {cm}^{ - 3}[/tex]
Hope you could get an idea from here.
Doubt clarification - use comment section.
A pitcher throws a softball
Answer:
Did you forget the answers
Explanation:
if so leave in comments and i will try to figure out
Answer:
what is the question and the answers??