Which is true according to the law of conservation of energy?
ОА.
In a closed system, the total amount of energy in the universe keeps on changing
The supply of energy is limited, so it is essential to conserve it.
OB.
OC.
In a closed system, energy can be created and destroyed.
0In a closed system, energy cannot be used faster than it is created
O E.
In a closed system, the total energy always remains constant OD
Answer: Last option (total energy always remains constant)
Explanation:
The Law of Conservation basically states that energy cannot be created or destroyed. Only changed from one form to another (potential, kinetic, chemical, etc.) so it makes sense that the net energy is unchanging.
it is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon. regardless of the initial excited state, this electron transition produces a spectral line in which region of the electromagnetic spectrum?
1. ultraviolet
2. infrared
3. visible light
4. radio waves
Answer:
1. Ultraviolet
Explanation:
This is called the Balmer series. Transitions ending in the ground state (n = 1) are called the Lyman series, but the energies released are so large that the spectral lines are all in the ultraviolet region of the spectrum.
It is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon. Regardless of the initial excited state, this electron transition produces a spectral line in ultraviolet region of the electromagnetic spectrum. The correct option is 1.
What is electromagnetic spectrum?An electromagnetic spectrum is the spectrum consisting of the colors of radiation of a white light with different wavelengths.
It is possible for an excited hydrogen atom to return to the ground state by the emission of a single photon.
The transitions which ends in the ground state (n = 1) are termed as Lyman series. Energy released is large in amount so that the spectral lines fall in the ultraviolet region of the spectrum.
Thus, regardless of the initial excited state, this electron transition produces a spectral line in ultraviolet region of the electromagnetic spectrum. The correct option is 1.
Learn more about electromagnetic spectrum.
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no files.
Please hurry I’m not trynna fail
Answer:
Larger, because both the Sun and Moon are pulling it.
Explanation:
what is work done aganist gravity?
Lifting an object and becomes potential energy of the object (Earth system). The change in gravity potential energy, ΔPEg, is ΔPEg = mgh.
With h being the increase in height and g the acceleration due to gravity.
I hope this helped :T
What is meant by a colored shadow? If "shadow" means
"absence of light," how can a shadow have a color?
Explanation:
Red, green, and blue are therefore called additive primaries of light. ... When you block two lights, you see a shadow of the third color—for example, block the red and green lights and you get a blue shadow. If you block only one of the lights, you get a shadow whose color is a mixture of the other two.
First, your definition of a shadow is incorrect. A shadow is an area that receives less light than its surroundings because a specific source of light is blocked by whatever is "casting" the shadow. Your example of being outside reveals this. The sky and everything around you in the environment (unless you are surrounded by pitch black buildings) is sending more than enough light into your shadow, to reveal the pen to your eyes. The sky itself diffuses the sunlight everywhere, and the clouds reflect plenty of light when they are not directly in front of the Sun.
If you are indoors and have two light bulbs, you can throw two shadows at the same time, possibly of different darknesses, depending on the brightness of the light bulbs.
It can take a lot of work to get a room pitch black. One little hole or crack in some heavy window curtains can be enough to illuminate the room. There are very few perfectly dark shadows.
An orange might roll of your cafeteria try when you stop suddenly because of
Answer:
Explanation:
Newton's first law of motion states that an object in motion stays in motion. The orange is moving and then the tray stops making the orange move forward because of inertia.
Answer:
The off the tray due to the inertia of motion
Explanation:
As we suddenly stop, the tray and our body comes to rest instantly they are in contact. The placed on tray and keeps moving due to the inertia of motion and hence roll of your tray
What is the function of Soda Line
A car has a mass of 2,000 kg and is traveling at 28m/s. What is the car’s kinetic energy?
984,000 J
784,000 J
484,000 J
Answer: i am not sure
Explanation: i am not sure
If the wavelength of an s-wave is 23,000 m, and its speed 4500 m/s, what is its frequency?
Answer:
5 metre.
Explanation:
Wavelength = Velocity / Frequency
= 23,000/ 4,500
= 5 metre.
The blocks shown in the pictures below are all made of wood. Which car will move the fastest?
Answer:
The one with the less mass
Explanation:
Volcanoes often form belts along plate boundaries. How does the piece of art illustrate that this statement holds true for North America? explain.
Answer:
The formation of volcanic arcs, trenches and subsidence leads to the production of volcanic eruptions.
Explanation:
North America plate makes a convergent boundary along with the pacific oceans. The is man reason for the development of the volcanoes and the origin of the earthquakes. The collusion of both these pales leads to the formation of a volcanic ring of fire that can be seen in the pacific ocean.what are the four eaemts
Answer:
The Four Elements in Everyday Life.
First Element: Earth. The earth is full of a wide variety of rocks and minerals which provides the soil to grow vegetation and support life. The two ...
Second Element: Water.
Third Element: Air.
Fourth Element: Fire.
Hope this help you!:)
Which situation would create a field like the one shown here?
A. interaction between two magnetic south poles
B. interaction between two magnetic north poles
C. interaction between a south pole and a north pole
D. interaction between a magnetic south pole and a copper bar
The liquid pressure exerted in one direction only
16= ? x4
What Makes The Equation True? Comment pls
Answer:
4
4x4=16
Explanation:
A tuning fork is struck against a hard surface. The particles in the tuning fork begin to vibrate quickly, transmitting a wave. What kind of wave does the tuning fork transmit?
Answer:
Longitudinal waves
Explanation:
Tuning forks create sound waves and sound waves are longitudinal
Two vehicles A and B accelerate uniformly from rest.
Vehicle A attains a maximum velocity of 30ms - in los
while B attains a maximum velocil) ol 40ms in the same
time. Both vehicles maintain these velocities for 6s belore
they are decelerated to rest in 6s and 4s respectively
Sketch on the same axes, velocity time graphs
for the motion of the vehicles
Calculate the velocity of each vehicle 18s aftur
the start. (VA
= 20ms -land vs
and vs = 20ms-')
How far will the two vehicles be from one
another during the moment in (ii) above?
(SA = 380m and SB
= 500m: SAB
120m). plz help
Answer:
(i) Please find attached the required velocity time graphs plotted with MS Excel
(ii) The velocity of vehicle A at the 18th second = 20 m/s
The velocity of vehicle B at the 18th second = 0 m/s
(iii) The distance between the two vehicles at the moment in (ii) above is 60 meters
Explanation:
The given parameters of the motion of vehicles A and B are;
The acceleration of vehicles A and B = Uniform acceleration starting from rest
The maximum velocity attained by vehicle A = 30 m/s
The time it takes vehicle A to attain maximum velocity = 10 s
The maximum velocity attained by vehicle B = 30 m/s
The time it takes vehicle B to attain maximum velocity = The time it takes vehicle A to attain maximum velocity = 10 s
The time duration vehicle A maintains its maximum velocity = 6 s
The time duration vehicle B maintains its maximum velocity = 4 s
(i) From the question, we get the following table;
[tex]\begin{array}{ccc}Time &V_A&V_B\\0&0&0\\10&30&40\\14&30&40\\16&30&20\\18&20&0\\22&0&\end{array}[/tex]
From the above table the velocity time graphs of vehicles A and B is created with MS Excel and can included here
(ii) The velocity of vehicle A at the start = 0 m/s
After accelerating for 10 seconds, the velocity of vehicle A = The maximum velocity of vehicle A = 30 m/s
The maximum velocity is maintained for 6 seconds which gives;
At 10 s + 6 s = 16 s, the velocity of vehicle A = 30 m/s
The time it takes vehicle A to decelerate to rest = 6 s
The deceleration of vehicle A, [tex]a_A[/tex] = (30 m/s - 0 m/s)/(6 s) = 5 m/s²
Therefore, we get;
v = u - [tex]a_A[/tex]·t
At the 18th second, the deceleration time, t = 18 s - 16 s = 2 s
u = 30 m/s
∴ v₁₈ = 30 - 5 × 2 = 20
The velocity of vehicle A at the 18th second, [tex]V_{18A}[/tex] = 20 m/s
For vehicle B, we have;
At the 14th second, the velocity of vehicle B = 40 m/s
Vehicle B decelerates to rest in, t = 4 s
The deceleration of vehicle B, [tex]a_B[/tex] = (40 m/s - 0 m/s)/(4 s) = 10 m/s²
For vehicle B, at the 18th second, t = 18 s - 14 s = 4 s
∴ [tex]v_{18B}[/tex] = 40 m/s - 10 m/s² × 4 s = 0 m/s
The velocity of the vehicle B at 18th second, [tex]v_{18B}[/tex] = 0 m/s
(iii) The distance covered by vehicle A up to the 18th second is given by the area under the velocity-time graph as follows;
The area triangle A₁ = (1/2) × 10 × 30 = 150
Area of rectangle, A₂ = 6 × 30 = 180
Area of trapezoid, A₃ = (1/2) × (30 + 20) × 2 = 50
The distance covered in the 18th second by vehicle [tex]S_A[/tex] = A₁ + A₂ + A₃
∴ [tex]S_A[/tex] = 150 + 180 + 50 = 380
The distance covered in the 18th second by vehicle [tex]S_A[/tex] = 380 m
The distance covered by the vehicle B in the 18th second is given by the area under the velocity time graph of vehicle B as follows;
Area of trapezoid, A₅ = (1/2) × (18 + 4) × 40 = 440
The distance covered by the trapezoid, [tex]S_B[/tex] = 440 m
The distance of the two vehicles apart at the 18t second, [tex]S_{AB}[/tex] = [tex]S_B[/tex] - [tex]S_A[/tex]
∴ [tex]S_{AB}[/tex] = 440 m - 380 m = 60 m
The distance of the two vehicles from one another at the 18th second, [tex]S_{AB}[/tex] = 60 m.
(Ecology) Food Chain lab Gizmo:
Before you interact with the simulation, what are your expecations? How will the food chain be effected if one organisim's population is altered? In your response, select one organisim (grass, rabbit, snake, hawk) and give a 3 sentence response on how you think a change in population of this organisim will impact the rest of the food chain.
Answer:
If the population of rabbits was altered then the food chain would be affected because if the population decreased then the animals that prey on rabbits wouldn't have as much food as they used to so the predators of the rabbits would decrease. If the population increased then the animals that prey on rabbits would increase. Overall, if rabbits had a change in population then the food chain would become effected, because if rabbits decrease then their predators decrease in population as well, the same goes for an increase in population.
(hope this helped!)
What was the initial velocity of a rock throw upwards if the velocity after 8 s is 90m/s?
Answer:
Initial velocity of rock = 11.6 m/s
Explanation:
Given:
Final velocity of rock = 90 m/s
Time taken by rock = 8 seconds
Find:
Initial velocity of rock
Computation:
Using first equation of motion;
v = u + at
For rock
v = u + gt
Acceleration due to gravity = 9.8 m/s²
90 = u + (9.8)(8)
90 = u + 78.4
u = 90 - 78.4
u = 11.6
Initial velocity of rock = 11.6 m/s
hi i need to pass this test im being timed please help
Answer:
C
Explanation:
What is the wave length of the instruments playing at this frequency if the speed of sound is 342m/s
Answer:
6.84m
Explanation:
The question you asked didn't specify the frequency of the instrument, so I'm going to assume for the question sake.
For the question, we will use the formula
λ = V/F, where
λ = the wavelength we're looking for
V = Velocity of the sound
F = frequency of sound.
Assuming that the frequency of the instrument is 50Hz.
λ = 342/50
λ = 6.84 m
All matter is NOT composed of __________.
A. protons
B. neutrons
C. sodium
D. electrons
(CORRECT ANSWER ONLY)
Answer:
C.
Explanation:
Answer:C
Explanation:
A 8.7kg cart travels down a 18.1m high hill. Determine the final kinetic energy if 100J of
energy is lost to friction.
Answer:
Explanation:
E = mgh
E(final) = E - friction
E(final) = 8.7 * 9.81 * 18.1 - 100 = 1444.8 J
1. Which of the following is
a reason you should drink water everyday?
A. Water praites uitamins.
B. Water proldes nutrients for daily functions
c Water praides energy
D. Water helps ashion gons and the spinal
cord
.
Answer:
B
Explanation:
Water is essential to most bodily functions.
A book falls from a shelf what would have the greatest effect on the velocity of the book as it falls to the ground
help asap!
three resistors of 20. ohms, 30. ohms, and 60. ohms, respectively, are connected in series with a battery. a current of 2.0 amperes will flow through this circuit when the potential difference of the battery is a. 20.V b. 220 V c. 110 V d. 10.V.
Answer:
b. 220 V
Explanation:
Let resistors be R1, R2, and R3 respectively.
Given the following data;
R1 = 20 ohms
R2 = 30 ohms
R3 = 60 ohms
Current = 2 Amperes
To find the voltage;
First of all, we would determine the total effective resistance (RT).
For series circuit;
RT = R1 + R2 + R3
RT = 20 + 30 + 60
RT = 110 Ohms
Next, we find the voltage using the formula;
Voltage = current * resistance
Voltage = 2 * 110
Voltage = 220 Volts
_______________________, _____________________, and _________, can help children prevent overweight and obesity. Obesity costs the US healthcare system $147 billion per ________.
Answer:
A.) healthy eating behaviors,
B.) regular physical activity,
C.) reduced sedentary activity
D.) year
Explanation:
healthy eating behaviors, regular physical activity, and reduced sedentary activity can help children prevent overweight and obesity.
Obesity costs the US healthcare system $147 billion per year.
Sodium has an atomic mass of 23 and an atomic number of 11, so the
number of neutrons must be_______
Answer here
Answer:
12 Neutrons
Explanation:
So the mass of sodium is 22.990. You round it up to get 23(as stated in the problem). So, what exactly is atomic mass?
Atomic Mass is the total amount of neutrons and protons added up to form a total mass. So when you subtract 23-11 you get 12 Neutrons.
Tip: Don't know if you need this but-
The neutrons and protons are typically close in number (unless it's an isotope). So say that you subtract and the numbers of protons and neutrons aren't close at all. Well if that's the case, it's probably wrong.
hope this helps!!
The
is the particle in the nucleus with a positive charge.
Answer here
Much of the pollution in out oceans comes from:
a.) car exhaust
b.) organic pesticides
c.) sewage and industrial waste
d.) fumes and smog
Answer:
c.) sewage and industrial waste