TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

Explain Why must a cooling system do work to transfer thermal energy?


Although internal energy will not spontaneously flow from a cold region to a hot region, it can be forced to do so by doing work on the system.Refrigerators and heat pumps are examples of heat engines which cause energy to be transferred from a cold area to a hot area. Usually this is done with the aid of a phase change, i.e., a refrigerant liquid is forced to evaporate and extract energy from the cold area. Then it is compressed and forced to condense in the hot area, dumping its heat of vaporization into the hot area. ARE YOU FROM K12?

Related Questions

Posted in Physics

Which of the following is not an example of kinetic energy? mechanical energy nuclear energy electrical energy thermal energy

It is only mechanical energy that is kinetic energy while the other choices are not kinetic energy. Nuclear, electrical and thermal are other types of energy. Hope this answers the question. Have a nice day. Feel free to ask more questions.

Posted in Physics

Nuclear reactions result in tremendous amounts of a. uranium. b. energy. c. fission. d. mass.

I believe the correct answer from the choices listed above is option B. Nuclear reactions result in tremendous amounts of energy. nuclear reaction is considered to be the process in which two nuclear particles interact to produce two or more nuclear particles or ˠ-rays. Hope this answers the question.

Posted in Physics

The heater in the thermostat control circuit in the cooling mode is active when the ____.

Here is the correct answer that would best complete the given statement above. The heater in the thermostat control circuit in the cooling mode is active when the heat anticipator in the thermostat control circuit is in the heating mode. Hope this is the answer that you are looking for. 

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

1. How many correct experiments do we need to disprove a theory? How many do we need to prove a theory? Explain. 2. A guidebook describes the rate of climb of a mountain trail as 120 meters per kilometer. How can you express this as a number with no units?

1.  You can never prove a theory. All theories and laws and scientific knowledge in general is provisional. If your theory is inconsistent with an experiment (and you are sure the experiment is correct), your theory needs to be pitched or modified.

2. 
change the meters to kilometers; 

120 m/km = .12 km/km = .12 

or the kilometers to meters; 

120 m/km = 120 m/1000m = .12 

This sounds like its telling you how far you climb vertically (.12 km) for every 1 km that you walk along the slanted, winding trail. 

The unitless number ".12" is usefull because now you can think of the rate of climb in any units you want. So you rise vertcally .12 miles for every mile you walk the trail, or you rise .12 ft for every foot you walk the trail, etc.

Posted in Physics

Where do plants get energy to live and grow?

From the sun, i think thats what it is. 

Posted in Physics

. How much work in joules is done by a person who uses a force of 25 N to move a desk 3.0 m?

We Know, W = F * s
here, F = 25 N
s = 3 m

Substitute it into the expression,
W = 25 * 3
W = 75 Joule

So, your final answer is 75 J

Hope this helps!

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

What property must a refrigerant of a cooling system have? Why?

Refrigeration compressors turn gases into high-pressure and -temperature gases, are also used to maintain a low boiling point.

Posted in Physics

Which is an example of transforming potential energy to kinetic energy? Check all that apply. changing thermal energy to electrical energy changing chemical energy to thermal energy changing nuclear energy to radiant energy changing radiant energy to electrical energy changing mechanical energy to chemical energy

When we say potential energy, this is the energy at rest. And kinetic energy is the energy at motion. So, here are the examples of energy that is transforming from potential energy to kinetic energy: changing thermal energy to electrical energy, and changing radiant energy to electrical energy. Hope this answer helps.

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

Please help! Find the tension in each cord in the figure if the weight of the suspended object is w = 210N A) Find the tension in the cord A for system (b). B) Find the tension in the cord B for system (b).

We have to solve the system of equations:
- T a * cos 60° + T b * sin 45° - 210 N = 0
- T a * sin 60° + Tb cos 45° =  0
------------------------------------------------------
- 1/2 T a + √2 / 2 T b = 210 N
- √3 / 2 T a + √ 2 / 2 T b = 0     / * ( - 1 )
---------------------------------------------------
- 1/2 T a + √2 / 2 T b = 210 N
√ 3 / 2 T a - √2 / 2 T b = 0
----------------------------------------
T a ( √3 / 2 - 1 / 2 ) = 210 N
0.366 T a = 210 N
T a = 210 N : 0.366
1 ) T a = 573.77 N
Ta * √3 / 2 = T b * √ 2 / 2
T b = ( 573.77 * 1.732 ) : 1.4142
2 ) T b = 702.7 N 

Posted in Physics

If two carts collide, what type of collision will conserve both momentum and kinetic energy? a. head on b. perfectly inelastic c. none d. perfectly elastic

The appropriate answer is d. perfectly elastic. When a perfectly elastic collision occurs both momentum and kinetic energy are preserved. Momentum is the mass of an object times its velocity while kinetic energy is the energy that a moving object has due to its motion. In an elastic collision kinetic energy would be converted to some other form of energy. 

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

Which scenario relates to Mayer and Salovey’s third component of emotional intelligence (regulating emotions)? A. gauging a friend’s anxiety in the absence of verbal cues B. reacting pleasantly to a friend’s practical joke C. understanding a friend’s problems and providing support D. determining the underlying cause of a friend’s nervous breakdown E. asking for a friend’s suggestion when working through a conflict

Option C i.e understanding a friend's problems and providing support is the correct answer.

Mayer and Salovey’s third component of emotional intelligence (regulating emotions) is the ability to Understand Emotions. So understanding a friend’s problems and providing support is the scenario relates to Mayer and Salovey’s third component of emotional intelligence (regulating emotions)

Posted in Physics

When would the temperature and thermal energy of an object differ?

The difference between temperature and thermal energy is that temperature measures the average kinetic speed of molecule and thermal energy is the total kinetic energy of all particles in a given substance.

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

Explain how power is determined within a context of electricity/circuitry

 Power (in watts) is the multiplication of voltage (in volts) and current (in amperes). P = VI 
and since, V = IR 
you also have 
P = I^2 R P = V^2 / R 

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

Which makes fast-moving water a greater force of erosion? A. greater heat capacity B. greater energy C. increased density D. greater oxidation

Answer:

B. Greater energy

Explanation:

Fast moving water is very energetic as its can displace very large rocks, boulders and make pebbles and sand out of them through the process r erosion. Fast moving water have kinetic energy, it opposes anything that come in its way. As river make its own channel by eroding plane. Many antecedent rivers have make their channel by cutting large mountains too.

Posted in Physics

Will an object with a density of 1.05 g/ml float or sink in water? Explain

The density of water at RTP is 0.998 g/ml so the object will sink in water due to its greater density.

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

The space shuttle travels at about 28,000 km per hour. Using that information, estimate how many hours it will take the shuttle to reach Saturn from Earth. Show your work. Convert your answer into scientific notation if necessary.

It depends what is the position of earth and saturn. Distance from earth to saturn varies depending on whether earth is between sun and saturn or sun is between earth and saturn. Obviously, the shortest distance will be if earth is between sun and saturn. we will take that the distance between earth and saturn is:

s = 1 275 000 000 km
The time required to travel that distance is:
t = s/v = 45535 hours or 1897.3 days

Posted in Physics

When an electric current is passed through water during the process of electrolysis, two gases are formed. One gas has a boiling point of -183 degrees celsius and the other has a boiling point of -253 degrees celsius. Has a physical change or a chemical change occurred? Explain.

The chemical change occurred. Electrolysis is used by scientists to make chemical reactions that wouldnt normaly spontaniously ocur. In this case we are getting new gases from water molecul which is change in structure of elements ( we are getting new moleculs)

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

What is transfered by electromagnetic waves?

electromagnetic waves transfer energy through matter or empty space; radio ultraviolet and gamma waves are a few. Produced by charged particles from the sun.

Posted in Physics

When an electron moves from a lower to a higher energy level the electron?

A photon is absorbed

your question is incomplete, please consider revising it.

Posted in Physics

Work is equal to _____. force times size velocity times force distance times force

Answer : The correct option is, distance times force

Explanation :

Work : It is defined as the force acting on an object to cause a displacement. Or we can defined as the work is equal to the product of the force of an object and displacement of an object.

The formula of the work is written as,

W=F\times d

where,

W = work done

F = force applied on an object

d = displacement of an object

Hence, the work is equal to distance times force.

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements

Posted in Physics

The temperature on the moon is A. hotter than the Earth most of the time B. goes from extremely cold to extremely hot during a lunar day C. about the same as the Earth D. colder than the Earth most of the time Please Explain

When the sun shines, it illuminates only one part of the moon. The article states, "Daytime on one side of the moon lasts about 13 and a half days, followed by 13 and a half nights of darkness. When sunlight hits the moon's surface, the temperature can reach 253 degrees F (123 C). The "dark side of the moon" can have temperatures dipping to minus 243 F (minus 153 C).Oct 22, 2012". Therefore, b is correct

Posted in Physics

Is it a good idea to drink beverages with caffeine when you are exercising? Explain your answer.

No you would barf, you need at least 30 minutes before you start working out or it could result in stomach issues.

TopAcademicTutors.Com

Expert Assignment Help for students who have pending assignments.

For 10$ a page, you can get your written essay.

Tell us your requirements