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
yarga [219]
3 years ago
13

The first law of thermodynamics can be given as ________.

Physics
1 answer:
MrRa [10]3 years ago
7 0
The first law of thermodynamics can be written as
\Delta U = Q-W
where
\Delta U is the variation of internal energy of the system
Q is the amount of heat absorbed by the system
W is the work done by the system on the surrounding.

Using this form, the sign convention for Q and W becomes:
Q > 0 --> heat absorbed by the system (because it increases the internal energy)
Q < 0 --> heat released by the system (because it decreases the internal energy)
W > 0 --> work done by the system (for instance, an expansion: when the system expands, it does work on the surrounding, and so the internal energy decreases, this is why there is a negative sign in the formula Q-W)
W < 0 --> work done by the surrounding on the system (for instance, a compression: when the system is compressed, the surrounding is doing work on the system, and so the internal energy of the system increases)
You might be interested in
A supersonic nozzle is also a convergent–divergent duct, which is fed by a large reservoir at the inlet to the nozzle. In the re
Lady_Fox [76]

Answer:

155.38424 K

2.2721 kg/m³

Explanation:

P_1 = Pressure at reservoir = 10 atm

T_1 = Temperature at reservoir = 300 K

P_2 = Pressure at exit = 1 atm

T_2 = Temperature at exit

R_s = Mass-specific gas constant = 287 J/kgK

\gamma = Specific heat ratio = 1.4 for air

For isentropic flow

\frac{T_2}{T_1}=\frac{P_2}{P_1}^{\frac{\gamma-1}{\gamma}}\\\Rightarrow T_2=T_1\times \frac{P_2}{P_1}^{\frac{\gamma-1}{\gamma}}\\\Rightarrow T_2=00\times \left(\frac{1}{10}\right)^{\frac{1.4-1}{1.4}}\\\Rightarrow T_2=155.38424\ K

The temperature of the flow at the exit is 155.38424 K

From the ideal equation density is given by

\rho_2=\frac{P_2}{R_sT_2}\\\Rightarrow \rho=\frac{1\times 101325}{287\times 155.38424}\\\Rightarrow \rho=2.2721\ kg/m^3

The density of the flow at the exit is 2.2721 kg/m³

4 0
3 years ago
Ohm's law states which relationship between electrical quantities? a. Volts = current x resistance b. Volts = current divided by
miv72 [106K]

Answer:

a. Volts = current x resistance

Explanation:

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

V = IR

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Hence, Ohm's law gives the relationship between voltage, current and resistance of an electric circuit.

7 0
2 years ago
What is Newton's gravitational constant ? write down its value and si unit.​
Irina18 [472]
Answer: 6.67 x 10^-11 m^3•kg^-1•s^-2
6 0
3 years ago
Longitudinal waves do not have
soldier1979 [14.2K]
E. Nonsense longitudinal waves have all of these properties
8 0
3 years ago
A wire is wrapped multiple times around a galvanized or aluminum nail and then each end of the wire connected to a battery for s
galina1969 [7]
Its A The paper clip is repelled away from the nail because an electromagnetic field magnetized to the nail
6 0
3 years ago
Read 2 more answers
Other questions:
  • What is wave polarization?
    5·1 answer
  • Cindy exerts a force of 40 N and moves a chair 6 m. Her brother and he pushes a different chair for 6 m while exerting a force o
    15·1 answer
  • Compare and contrast the velocity at which X-rays and radio waves travel
    9·2 answers
  • Water flows from the bottom of a storage tank at a rate of r(t) = 300 − 6t liters per minute, where 0 ≤ t ≤ 50. Find the amount
    15·1 answer
  • Which of the following has the most potential energy?
    5·2 answers
  • Which of the following is NOT a skill scientists use to learn about the world?
    13·1 answer
  • What happens to the frequency of a wave If the wavelength is decreased by half
    10·1 answer
  • A football is kicked from a tee at 12 m/s at 72° above the horizontal. What is the maximum height of the football
    11·1 answer
  • 1) Calculate the torque required to accelerate the Earth in 5 days from rest to its present angular speed about its axis. 2) Cal
    13·1 answer
  • Red light has a wavelength of (7. 21x10^7)m. What is the frequency of this light?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!