PLS HELP BEING TIMED!!!
Which equation represents the law of conservation of energy in a closed system?

KEi + PEi = KEf + PEf
PEi + PEf = KEi + KEf
KEi – KEf = PEi – PEf
KEi – PEf = PEi – KEf

Answers

Answer 1

Answer:

[tex]K_{i}+U_{g,i} = K_{f}+U_{g,f}[/tex]

Explanation:

A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:

[tex]\Delta K +\Delta U_{g} = 0[/tex] (1)

Where:

[tex]\Delta K[/tex] - Change in kinetic energy of the system, measured in joules.

[tex]\Delta U_{g}[/tex] - Change in gravitational potential energy of the system, measured in joules.

If we know that [tex]\Delta K=K_{i}-K_{f}[/tex] and [tex]\Delta U_{g} = U_{g,i}-U_{g,f}[/tex], then we get the following equation:

[tex]K_{i}+U_{g,i} = K_{f}+U_{g,f}[/tex] (2)

Where [tex]i[/tex] and [tex]f[/tex] stands for initial and final states of each energy component.

Hence, the right answer is [tex]K_{i}+U_{g,i} = K_{f}+U_{g,f}[/tex]

Answer 2

Answer:

KEi + PEi = KEf + PEf

Explanation

right on edge 2020


Related Questions

A car travels 14 km due west, then does a
U-turn, and travels 43 km due west.
I. What total distance has the car
traveled?
II.
What is the total displacement of the
car?
III. If the entire trip took 3.20 hours.
determine the average speed of the
car. Give
your answer in both
km hour, and m s. (show
conversion)
IV. If the entire trip took 2.50 hours.
determine the average velocity of
the car. Give your answer in both
km h, and mph (show conversion)

Answers

Explanation:

It is given that,

A car travels 14 km due west, then does a U-turn and travels 43 km due east (when it takes U-turn, it will change direction from west to east)

i. Total distance = total path covered

= 14 km + 43 km

= 57 km

ii. Let east is positive and west is negative.

Displacement = final position-initial position

= 43-14

= 29 km

iii. If time taken in the entire trip = 3.2 hours

Average speed = distance/time

[tex]s=\dfrac{57\ km}{3.2\ h}\\\\=17.81\ km/h[/tex]

1 km/h = 0.2777 m/s

17.81 km/h = 4.94 m/s

iv. If time taken in the entire trip = 2.5 hours

Average velocity = displacement/time

[tex]v=\dfrac{29\ km}{2.5\ h}\\\\=11.6\ km/h[/tex]

1 km/h = 0.621 mph

11.6 km/h = 7.2 mph

Henc, this is the required solution.

A car travels east at a constant velocity. The net force on the car is:

Answers

F=ma
As velocity is constant, a=0
So, F=0

Hope this helps!

please help !!!!! I’ll give brainliest !

Answers

Answer:

Honestly for me it's a bit too blurry. Sorry luv.:(

Explanation:


What is the awnser to that question

Answers

The answers To your question is c
Should be C cuz think about it, if you are in a bus and there is a person to the right of you it looks like he’s moving in the opposite direction of the bus at the soles of the bus

a person has gotten a new job with a much higher salary. he plans to spend his extra money on a new car and a great stereo system for his apartment.

Answers

Answer:

He will get a higher sales and income tax

Explanation:

just took the quiz and got it right

The person with a new job of a much higher salary and a new car and a great stereo system for his apartment, will attract more tax.

Effect of tax on higher salaries and properties

PAYE which is an acronym for pay as you earn,  is a form of tax deducted by an employer from the employee's salaries and wages.

As the person earns higher, his income tax increases, as he acquires more luxury properties, his personal tax increases as well.

Thus, the person with a new job of a much higher salary and a new car and a great stereo system for his apartment, will attract more tax.

Learn more about taxes here: https://brainly.com/question/1775528

#SPJ2

which one?? please someone quick!​

Answers

Answer:

i think its second law of motion.

Explanation:

Answer:

it’s the second law

Explanation:

The voltage between two points in a circuit is 4.2 V. If the resistance between
the points is 72, what is the current, according to Ohm's law?
A. 0.058 A
B. 76.2 A
O C. 17.1 A
O D. 302 A

Answers

Answer:

I = 0.058 [A]

Explanation:

Ohm's law is defined as voltage equal to the product of current by resistance.

[tex]V =I*R[/tex]

where:

V = voltage = 4.2 [V]

I = current [amp]

R = resistivity = 72 [ohm]

Now clearing I, we have:

[tex]I = V/R\\I = 4.2/72\\I = 0.058 [A][/tex]

Answer:

A. 0.058 A

Explanation:

why is thouching the live wire of an appliane when it is connecfed to the mains dangerous

Answers

Answer: The live wire is the most dangerous one, since it is at 230 V. it should never touch the earth wire (unless the insulation is between them, of course!), because this would make a complete circuit from your mains supply to the ground (earth). A shock or fire would be highly likely.

Explanation:


A 1 kg puck sliding on a horizontal shuffleboard court is slowed to rest by 1 point
a frictional force of 3 N. What is the coefficient of kinetic friction between
the puck and the surface of the shuffleboard court? *
O A. 0.25
O B.0.5
O c.0.15
D. .31

Answers

Answer:

miu = 0.31

Explanation:

The friction force is defined as the product of the normal force by the coefficient of friction.

[tex]f=miu*N[/tex]

where:

f = friction force = 3 [N]

miu = friction coefficient

N = normal force [N]

The normal force on a horizontal surface can be calculated by means of the product of mass by gravity.

where:

m = mass = 1 [kg]

g = gravity acceleration = 9.81 [m/s²]

[tex]N=m*g\\N=1*9.81[/tex]

[tex]N= 9,81 [N][/tex]

Now replacing in the equation above, we can find the friction coefficient.

[tex]miu=3/9.81\\miu = 0.31[/tex]

What causes wind?
A
The sun stops the wind throughout the afternoon as everything warms up.
B
The sun causes waves to be larger by directing solar energy into the water.
C
The sun heats land quickly and as the warm air rises, cool air comes in to take it place.
D
The sun reflects off the water, making the air above the water unstable and more likely to move.

Answers

Answer:C

Explanation:

The sun heats land quickly and as the warm air rises, cool air comes in to take it place.

Answer:

C

Explanation:

Select the correct answer.
Which two factors does the power of a machine depend on?
Α. work and distance
B. force and distance
C. work and time
D. time and distance

Answers

Answer: C. work and time

Explanation: hope this helps

How are electrons involved in the formation of a bond between atoms?

Answers

Answer:

5

Explanation:

electrons can be more than det


A man has a mass of 85 kg. What is his weight?

Answers

he weights 187.393 pounds

Answer:833N

Explanation: A. P. E. X.

Which is an example of negative acceleration?

Answers

A graph that starts from the top left decreasing to the bottom right

The water cycle was described in the Scriptures long before modern scientists understood it.


True False

Answers

Answer:

False

Explanation:

Low humidity is typically associated with cold temperatures since cold air holds less water compared to warm air. While it is possible for indoor humidity to be as low as 10%, most people generally find humidity levels of about 40 to 45 percent comfortable.

false... HOPE THIS HELPS!!!

Explain you own words why energy is considered to be naturals money. Give an example to support your explanation

Answers

Answer:

because we naturally use energy everyday in everyway , energy is also a bill for instance you electric bill used by energy

Explanation:

Which of the following is an example of the Doppler effect? (2 points)
A. A water bug on the surface of a pond is producing small ripples in the water. The bug is not moving
B. A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
C. Scientists measure the speed of light and find that it is constant.
D. The gravitational pull of two objects on each other

Answers

Answer: B

Explanation:

Your'e asking about how waves get closer and louder A it isn't moving so no, C it's not saying if it's near or not and D is going trough another procedure so that leaves B behind

When electrons are moving freely between many positive ions, what type of bond is occuring?

a
metallic
b
ionic
c
covalent
d
crystalline

Answers

Answer:

a metallic

Explanation:

Metal atoms are joined together by metallic bonds. Metals can form cations (positive ions) with a sea of delocalized electrons.

Which of the following for an object should be known to calculate its density? (5 points)
A.the heat present in it
B.The amount of matter in it
C.The force of gravity acting on it
D.The space between the object and another object

Answers

I think d

explaination
i think its d because density is like how much it weighs??

What do we call the potential mechanical energy stored in an object when work is performed to change its shape?
A.) elastic energy
B.) sound energy
C.) kinetic energy

Answers

c) kinetic energy :)

Describe the effect of speed on voltage

Answers

Answer:

Speed has no effect on voltage.

Explanation:

The voltage of the battery in your car is always 12 to 13.5 volts. It makes no difference whether the car is home in the garage or zooming down the interstate.

Hee Sun drew an electron dot diagram of a silicon atom as shown.

S i with 1 dot each above, right, below, left.

In addition to changing the symbol to C, how would this diagram compare with an electron dot diagram of a carbon atom (C)?

The dot to the left of the symbol would be removed in the diagram for carbon.
The same number of dots would appear in the diagram for carbon.
There would be two dots above and to the right of the symbol in the diagram for carbon.
The single dots would be replaced with two dots on each side of the symbol in the diagram for carbon.

Answers

Answer:

B

Explanation:

I took the test uwu

Answer:

B. The same number of dots would appear in the diagram for carbon.

Explanation:

took the test and got 100%  

What is the mass of a crate if a net force of 12 N gives the crate an acceleration of 0.20 m/s2?

Answers

A :-) for this question , we should apply
F = ma
Given - F = 12 N
a = 0.20 m/s^2
Solution -
F = ma
12 = m x 0.20
m = 12 by 0.20
m = 60 kg

.:. The mass is 60 kg.

What wavelength would a ripple in water have if the frequency is 1.8 Hz and a
wave speed of 825 m/s?

Answers

Explanation:

825m/s / 1.8Hz = 458.33m

λ=v/f

λ-wavelength

v-speed

f-frequency

λ=825/1.8=458.33m

A 0.152 kg ball is attached to a string that is 62.2 cm long. The string will break if subjected to a tension force of 4.8 N. If a small child swings the ball in a horizontal circle around her head, at what velocity will the string break?

Answers

Answer:

The value is  [tex]v = 3.68 \ m/s[/tex]

Explanation:

From the question we are told that

   The mass the ball is  [tex]m = 0.152 \ kg[/tex]

    The length of the string is [tex]l = 62.2 \ cm = 0.622 \ m[/tex]

      The tension of force that will break the string is [tex]T = 4.8 \ N[/tex]

Generally the radius of the circle made by swinging the  string is  [tex]r = l = 0.622\ m[/tex]

     Generally the centripetal force acting on the ball is mathematically represented as  

              [tex]F_c = \frac{mv^2}{r}[/tex]

Generally this centripetal force is mathematically represented as

          [tex]F_c = T - mg[/tex]

=>       [tex]T - mg = \frac{mv^2}{r}[/tex]

=>      [tex]4.8 - 0.152 * 9.8 = \frac{0.152 * v^2}{0.622}[/tex]

=>      [tex]v = 3.68 \ m/s[/tex]

Explain how scientist learned about the magnetic poles of the Earth.

Answers

Answer:

there are many way but this may help

Explanation:

The tendency of a magnet to align itself in a north-south direction, so giving a magnetic compass, was discovered by the Chinese about 2000 years ago. Then in 1600 William Gilbert published De Magnete, in which he concluded that the earth behaved as a giant magnet. ...

Which statement describes how this diagram could be changed so that it
shows an electromagnet?
so
Battery
Ammeter
A. Place a second battery between the ammeter and the wire coil.
B. Add a magnetic metal core inside the coil of wire.
C. Add magnetic field lines around the wire coil,
D. Move the ammeter to the other side of the wire coil.

Answers

Answer:

b. add a magnetic metal core

Explanation:

a p e x test

Answer:

B. Add a magnetic metal core inside the coil of wire.

Explanation:

3. Riddle:
I am black when you buy me, red when you use me and grey when you throw me away.
What am I?

Answers

Answer:

The answer is charcoal

Answer:

Charcoal

Explanation:

what is meant by absolute zero temperature?​

Answers

Answer:

Absolute zero, temperature at which a thermodynamic system has the lowest energy. It corresponds to −273.15 °C on the Celsius temperature scale and to −459.67 °F on the Fahrenheit temperature scale.

Absolute zero isn't even zero on the temperature scales used by nonscientists. It's minus 273.15 degrees on the Celsius scale, or minus 459.67 degrees Fahrenheit

Studying neutrinos helped to explain how our Sun works but led to changes in theories of particle physics, how is this process consistent with the scientific process? How can details about a theory be adjusted without undermining other discoveries made through the theory's predictions?

Answers

Explanation:

Yes,  evidently, the process is consistent with the scientific process because in scientific process falsification and modification are two very important traits. So this new concept have modified the existing theories.

Through the modification a theory is adjusted without undermining other discovering made through the theory's prediction.

There are many other evidences that prove this fact for example Einstien's Theory of relativity also changes the existing concepts.

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