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
Anon25 [30]
3 years ago
14

In the context of energy transfers with hot and cold reservoirs, the sign convention is that _______________.

Physics
1 answer:
Likurg_2 [28]3 years ago
8 0

Answer:

B. QC > 0; QH < 0

Explanation:

Given that there are two reservoir of energy.

Sign convention for heat and work :

1.If the heat is adding to the system then it is taken as positive and if heat is going out from the system then it is taken as negative.

2. If the work is done on the system then it is taken as negative and if the work is done by the system then it is taken as positive.

From hot reservoir heat is going out that is why it is taken as negative

Q_H

From cold reservoir heat is coming inside the reservoir that is why it is taken as positive

Q_C>0

That is why the answer will be

Q_H ,Q_C>0

You might be interested in
An object in projectile motion will follow which path? a]curved up from the ground b]curved down toward the ground c]straight do
Lesechka [4]
It's B because when you throw something it doesn't go up it slowly descends downward
7 0
3 years ago
Read 2 more answers
The photons of different light waves:
LuckyWell [14K]

Answer: contain different amounts of energy

Explanation:

The energy E of a photon is given by:

E=h\nu

Where:

h=6.626(10)^{-34}\frac{m^{2}kg}{s} is the Planck constant

\nu is the frequency of the light which is inversely related to the wavelength.

Now, if we have photons of different light waves, this means we have photons with different frequencies.

As the energy of the photon depends on its frequency:

Photons of different light waves <u>contain different amounts of energy.</u>

8 0
3 years ago
During which two time intervals does the particle undergo equal displacement?
san4es73 [151]

Answer:

BC and DE

Explanation:

In the given figure, the velocity time graph is shown. We know that the area under v-t curve gives the displacement of the particle.

Area under AB, d_1=\dfrac{1}{2}\times 2\times 10=10\ m

Area under BC, d_2=\dfrac{1}{2}\times 2\times 4=4\ m

Area under CD, d_3=\dfrac{1}{2}\times 2\times 7=7\ m

Area under DE, d_4=\dfrac{1}{2}\times 2\times 4=4\ m

Area under EF, d_5=\dfrac{1}{2}\times 2\times 3=3\ m

So, form above calculations it is clear that, during BC and DE undergo equal displacement. Hence, the correct option is (c) "BC and DE = 4 meters".

4 0
3 years ago
How many lines per mm are there in the diffraction grating if the second order principal maximum for a light of wavelength 536 n
grandymaker [24]

To solve this problem it is necessary to apply the concepts related to the principle of superposition and the equations of destructive and constructive interference.

Constructive interference can be defined as

dSin\theta = m\lambda

Where

m= Any integer which represent the number of repetition of spectrum

\lambda= Wavelength

d = Distance between the slits.

\theta= Angle between the difraccion paterns and the source of light

Re-arrange to find the distance between the slits we have,

d = \frac{m\lambda}{sin\theta }

d = \frac{2*536*10^{-9}}{sin(24)}

d = 2.63*10^{-6}m

Therefore the number of lines per millimeter would be given as

\frac{1}{d} = \frac{1}{2.63*10^{-6} }

\frac{1}{d} = 379418.5\frac{lines}{m}(\frac{10^{-3}m}{1 mm})

\frac{1}{d} = 379.4 lines/mm

Therefore the number of the lines from the grating to the center of the diffraction pattern are 380lines per mm

6 0
3 years ago
How do the chemical properties of the halogens compare to those of the noble gases?
serg [7]
Halogens<span> are extremely reactive elements because they need one more electron to gain a full octet of valence electrons, whereas the </span>noble gases<span>are extremely unstable because they already have their full octet.</span>
8 0
3 years ago
Other questions:
  • Yellow light is incident upon a medium from air at an angle of 45.0°. The light bends toward the normal and refracts at 28.0°. W
    9·2 answers
  • 。and 。 are needed to describe a force
    15·1 answer
  • Why are some pots and pans design with wooden handles?
    9·2 answers
  • TRUE OR FALSE: ancient swamp plants slowly decayed and turned into peat, the first step in making coal.
    5·2 answers
  • A plane flying horizontally above earth’s surface at 100. meters per second drops a crate. the crate strikes the ground 30.0 sec
    9·1 answer
  • What causes air to become less dense and rise?
    5·1 answer
  • an aircraft has a liftoff speed of 53 m/s. what is the minimum constant acceleration an airplane must have to reach that takeoff
    14·1 answer
  • a red kangaroo can hop at speeds of 65 km/hr. how much time will it take the kangaroo to hop 0.25 km at that speed?
    10·1 answer
  • An electrical circuit is a portable device that converts chemical energy into electrical energy
    6·1 answer
  • Why is “soft” iron used for the core of an electromagnet?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!