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
tigry1 [53]
3 years ago
13

When a system is heated, heat is _______________ by the system. The amount of heat added is given a _______________ sign. When a

system is cooled, heat is _______________ by the system. The amount of heat is given a _______________ sign. If a gas expands, it must push the surrounding atmosphere away. Thus, work is done _______________ the system and is given a _______________ sign. If a gas is compressed, then work is done _______________ the system. This work is given a _______________ sign.
Physics
2 answers:
Valentin [98]3 years ago
7 0

First of all, we need to write the First Law of thermodynamics assigning the correct sign convention:

\Delta U = Q+W

where

\Delta U is the change in internal energy of the system

Q is the heat absorbed/released

W is the work done

and the signs are assigned based on whether there is an increase in the internal energy or not. Therefore:

Q is positive if it is absorbed by the system (because internal energy increases)

Q is negative if it is released by the system (because internal energy decreases)

W is negative if it is done by the system on the surrounding (because internal energy decreases)

W is positive if it is done by the surrounding on the system (because internal energy increases)

Using these definitions, we can now fill the text of the question:

When a system is heated, heat is ABSORBED by the system. The amount of heat added is given a POSITIVE sign. When a system is cooled, heat is RELEASED by the system. The amount of heat is given a NEGATIVE sign. If a gas expands, it must push the surrounding atmosphere away. Thus, work is done BY the system and is given a NEGATIVE sign. If a gas is compressed, then work is done ON the system. This work is given a POSITIVE sign.

Makovka662 [10]3 years ago
6 0

Answer:

When a system is heated, heat is ABSORBED by the system. The amount of heat added is given a POSITIVE sign. When a system is cooled, heat is RELEASED by the system. The amount of heat is given a NEGATIVE sign. If a gas expands, it must push the surrounding atmosphere away. Thus, work is done BY the system and is given a NEGATIVE sign. If a gas is compressed, then work is done ON the system. This work is given a POSITIVE sign.

Explanation:

You might be interested in
As the population in a small town grows, a new water treatment plant is built. The plant is built on a local river where it can
abruzzese [7]

Treatment water from the plant would affects the communities present in the downstream of the river.

Answer: Option (a)

<u>Explanation:</u>

Wastewater treatment plant is a process used to treat the water that flows from the rivers, streams, and lakes.This plant removes the dust, sand, sediments present in the river water.

When this treated water is released into the downriver stream, it affects the health of aquatic organisms present in that stream.Use of chemicals in treating the wastewater may cause genetic problems to the communities present in that region.

It also causes air pollution and more energy is needed for the treatment process and thus affects the ecosystem.

6 0
3 years ago
Read 2 more answers
These are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine that have created a hole in the oz
yarga [219]
Hello! The nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine that have created a hole in the ozone layer are the Chlorofluorocarbons (CFCs)

These are compounds developed and improved by Thomas Midgley in the late 1920s. They were used as refrigerants and aerosol propellants.

These compounds created a hole in the ozone layer by the following reactions:

CCl₃F → CCl₂F· + Cl· (In the presence of light. Radical Reaction)
Cl· + O₃ → ClO + O₂
ClO + O₃ → Cl· + O₂ 

The last 2 reactions can repeat in a radical mechanism and explain why these compounds are so harmful to the ozone layer. 
4 0
4 years ago
An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the tri
Anettt [7]

Answer:

270 mi/h

Explanation:

Given that,

To the south,

v₁ = 300 mi/h, t₁ = 2 h

We can find distance, d₁

d_1=v_1\times t_1\\\\d_1=300\times 2\\\\d_1=600\ \text{miles}

To the north,

v₂ = 250 mi/h, d₂ = 750 miles

We can find time, t₂

t_2=\dfrac{d_2}{v_2}\\\\t_2=\dfrac{750\ \text{miles}}{250\ \text{mi/h}}\\\\t_2=3\ h

Now,

Average speed = total distance/total time

V=\dfrac{d_1+d_2}{t_1+t_2}\\\\V=\dfrac{600+750}{2+3}\\\\V=270\ \text{mi/h}

Hence, the average speed for the trip is 270 mi/h.

3 0
3 years ago
Please help I'll mark brainliest!!!!
madam [21]

This question is based on the fundamental assumption of  vector direction.

A vector is  a physical quantity which has  magnitude as well direction  for its complete specification.

The magnitude of a physical quantity is simply a  numerical number .Hence it can not be negative.

A negative vector is a vector which comes into existence when it is opposite to our assumed direction with respect to any other vector.  For instance, the vector is taken positive if it is along + X axis and negative if it is along - X axis.

As per the first option it is given that a vector is negative if its magnitude is greater than 1. It is not correct as magnitude play no role in it.

The second option tells that the magnitude of the vector is less than 1. Magnitude can not be negative. So this is also wrong.

Third one tells that a vector is negative if its displacement is along north. It does not give any detail information about the negativity of a vector.

In a general sense we assume that vertically downward motion  is negative and vertically upward is positive. In case of a falling object the motion is  vertically downward. So the velocity of that object is negative .

So last   option is  partially  correct  as  the vector can be negative depending on our choice of co-ordinate system.





7 0
3 years ago
Read 2 more answers
These are intense, rotating convectional systems that develop over warm ocean areas in the tropics and subtropics, primarily dur
asambeis [7]

Answer:

True.

Explanation:

During the late summers the SST (sea surface temperature) rises the most which made the wind above the sea moist and warm. Global warming is also one of the cause of the rise in sea surface temperatures. Then the Coriolis effect due to the earth's rotation make these winds to rotate which results in the formation of the cyclones mostly in the areas near to equator.

4 0
3 years ago
Other questions:
  • A discus thrower achieves a high throw of 100m with the discus released at an angle of 30° calculate the initial speed of the di
    15·1 answer
  • two object gravitationally attract with a force of 20N.if the distance between the two object centers is doubled, then what is t
    12·1 answer
  • Verify that for values of n less than 8, the system goes to a stable equilibrium, but as n passes 8, the equilibrium point becom
    5·1 answer
  • If 2 balls have the same volume, but ball A has twice as much mass as ball B, which one will have the greater density
    10·1 answer
  • Compared to a cold object, a hotter object of the same size emits most of its light at __________ wavelengths and emits _____ li
    15·1 answer
  • A particle with charge 8 µC is located on the
    7·1 answer
  • What form of energy transforms to what other form when you turn on a steam iron?​
    10·1 answer
  • Lauren is comparing rocks from two different locations. She has the following
    14·1 answer
  • A 0.772 kg glass jar falls off a shelf
    12·1 answer
  • What does it mean when something says Expert Verified?<br><br> I am Marking brainliest!
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!