1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Sever21 [200]
3 years ago
12

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

Physics
1 answer:
aleksandrvk [35]3 years ago
8 0
Although internal energy<span> 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.</span>Refrigerators<span> and </span>heat pumps<span> are examples of </span>heat engines<span> which cause energy to be transferred from a cold area to a hot area. Usually this is done with the aid of a </span>phase change<span>, 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 </span>heat of vaporization<span> into the hot area. ARE YOU FROM K12?</span>
You might be interested in
Which type of seismic wave can only pass through the earths mantle?
mezya [45]
Secondary wave is the answer 

6 0
4 years ago
An electron traveling at a velocity v enters a uniform magnetic field B. Initially, the velocity and field are perpendicular to
Brut [27]

If the electron goes a distance d, the amount of work done on it by the magnetic field is zero.

Because magnetic force acts perpendicular to the direction of motion, it has no effect on any moving charge particle. As a result, speed won't change.

<h3>What is Magnetic field?</h3>
  • The magnetic influence on moving electric charges, electric currents, and magnetic materials is described by a magnetic field, which is a vector field.
  • A force perpendicular to the charge's own velocity and the magnetic field acts on it when the charge is travelling through a magnetic field.
  • A compass, a motor, the magnets that hold items in refrigerators, railroad tracks, and modern roller coasters are examples of devices that use magnetic force.
  • A magnetic field is created by all moving charges, and any charges that move across its regions are subject to a force.

Learn more about Magnetic field here:

brainly.com/question/14848188

#SPJ4

6 0
2 years ago
Sarah invested 12000 in a unit trust 5 years ago, the value of the unit trust has increased by 7% per annum for the last 3 years
miss Akunina [59]

Answer:

The value of the fund today is $13831.72

Explanation:

Let us calculate the value at the end of each year, step by step. An annual  decrease of 3% corresponds to a multiplier 1.0-0.03 = 0.97. An increase of 7% corresponds to 1.07.

Value at the end of

year 1: 12000 * 0.97

year 2: 12000 * 0.97 * 0.97

year 3: 12000 * 0.97 * 0.97 * 1.07

year 4: 12000 * 0.97 * 0.97 * 1.07 * 1.07  

year 5: 12000 * 0.97 * 0.97 * 1.07 * 1.07 * 1.07 = 13831.72

The value of the fund today (end of year 5) is $13831.72

8 0
4 years ago
Read 2 more answers
What is the quality of the sound of a fire truck’s siren when it moves toward a stationary hearer?
Doss [256]
<span>What is the quality of the sound of a fire truck’s siren when it moves toward a stationary hearer?
Its High Pitched

</span>

What is the quality of the sound of a fire truck’s siren when it moves away from a stationary hearer?

Its Low Pitched

6 0
3 years ago
Read 2 more answers
A 0.5 kg block of aluminum (caluminum=900J/kg⋅∘C) is heated to 200∘C. The block is then quickly placed in an insulated tub of co
Genrish500 [490]

Answer: When 1.0kg of aluminium block is used, the final temperature of the mixture will be T = 36.2∘C

If 1.0kg copper block is used, T of the mixture will be = 17.4∘C

If 100g (0.1kg) of ice at 0∘C is used, T will be = 64.9∘C

If 25g (0.025Kg) of ice is used, T will be= 147.1∘C

Explanation:

H = mcΘ

heat lost by block = heat gained by water

m₁c₁Θ₁ = m₂c₂Θ₂ where m₁ is mass of aluminium, m₂ is mass of water, c₁ is cAluminium, c₂ is cWater, Θ₁ is temperature change for aluminium, Θ₂ is temperature change for water.

0.5*900*(200-20) = m₁*4186*(20-0)

m₁ = 450*180/83270

<em>m₁ = 0.973kg</em>

<em>when 1.0kg of aluminium block is used, the final temperature of the mixture will be </em><em>T</em>

heat lost by block = heat gained by water

1.0*900*(200-T) = 0.973*4186*(T-0)

180000 - 900T = 4073T

4973T = 180000

T = 180000/4973 = 36.2∘C

<em>If 1.0kg copper block is used, T of the mixture will be</em>

heat lost by block = heat gained by water

1.0*387*(200-T) = 0.973*4186*(T-0)

77400 - 387T = 4073T

4460T = 77400

T = 77400/4460 = 17.4∘C

<em>If 100g (0.1kg) of ice at 0∘C is used, T will be</em>

<em>heat lost by block = heat gained by water + heat used in melting ice to form water at 0∘C</em>

heat used in melting 0.1kg of ice, H = ml, where l= 33600J/Kg

0.5*900*(200-T) = 0.1*4186*(T-0) + 0.1*33600J/Kg

90000 - 450T =  418.6T + 33600

418.6T + 450T = 90000 - 33600

868.6T = 56400

T = 56400/868.6 = 64.9∘C

If 25g (0.025Kg) of ice is used, T will be

0.5*900*(200-T) = 0.025*4186*(T-0) + 0.025*33600J/Kg

90000 - 450T =  104.65T + 8400

104.65T + 450T = 90000 - 8400

554.65T = 81600

T = 81600/554.65 = 147.1∘C

7 0
3 years ago
Other questions:
  • A rocket starting from its launch pad is subjected to a uniform acceleration of 100 meters/second2. Determine the time needed to
    11·1 answer
  • When a certain ideal gas thermometer is immersed in a water-ice mixture at 273.15 K, the mercury level in the right arm is 102 m
    7·1 answer
  • Suppose a piece of dust finds itself on a CD. If the spin rate of the CD is 500 rpm, and the piece of dust is 4.3 cm from the ce
    6·1 answer
  • Lena is studying the properties of light in a laboratory. If she increases the amplitude of the light waves she is studying, wha
    11·1 answer
  • PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!
    5·2 answers
  • In the open ocean, the distance between wave
    8·1 answer
  • What is the average distance between Miranda and uranus
    12·2 answers
  • A train is traveling at 28 m/s. It slows to 6 m/s in 4 s. Calculate the distance the train
    13·2 answers
  • A charged particle moving in the magnetic field. For which angle magnetic force acting on charged particle is maximum.? ​
    11·1 answer
  • What is the ratio of the average distances that oxygen will diffuse in a given time in air and water
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!