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
stepan [7]
3 years ago
5

Newton's law of cooling states that the rate of change of temperature of an object in a surrounding medium is proportional to th

e difference of the temperature of the medium and the temperature of the object. Suppose a metal bar, initially at temperature 50 degrees Celsius, is placed in a room which is held at the constant temperature of 40 degrees Celsius. One minute later the bar has cooled to 40.18316 degrees . Write the differential equation that models the temperature in the bar (in degrees Celsius) as a function of time (in minutes). Hint: You will need to find the constant of proportionality. Start by calling the constant k and solving the initial value problem to obtain the temperature as a function of k and t . Then use the observed temperature after one minute to solve for k .
Physics
1 answer:
sineoko [7]3 years ago
6 0

Answer:

Newton's law of cooling says that the temperature of a body changes at a rate proportional to the difference between its temperature and that of the surrounding medium (the ambient temperature); dT/dt = -K(T - Tₐ) where T = the temperature of the body (°C), t = time (min), k = the proportionality constant (per minute),

Explanation:

You might be interested in
An engine draws energy from a hot reservoir with a temperature of 1250 K and exhausts energy into a cold reservoir with a temper
dimulka [17.4K]

Answer:

The power output of this engine is  P =  17.5 W

The  the maximum (Carnot) efficiency is  \eta_c  = 0.7424

The  actual efficiency of this engine is  \eta _a  = 0.46

Explanation:

From the question we are told that

    The temperature of the hot reservoir is  T_h = 1250 \ K

      The temperature of the cold reservoir  is  T_c  =  322 \ K

     The energy absorbed from the hot reservoir is E_h  = 1.37 *10^{5} \ J

       The energy exhausts into  cold reservoir is  E_c  = 7.4 *10^{4} J

The power output is mathematically represented as

      P  =  \frac{W}{t}

Where t is the time taken which we will assume to be 1 hour =  3600 s  

W is the workdone which is mathematically represented as

      W =  E_h  -E_c

substituting values

       W = 63000 J

So

    P =  \frac{63000}{3600}

    P =  17.5 W

The Carnot efficiency is mathematically represented as

          \eta_c  =  1 - \frac{T_c}{T_h}

         \eta_c  =  1 - \frac{322}{1250}

         \eta_c  = 0.7424

The actual efficiency is mathematically represented as

        \eta _a  =   \frac{W}{E_h}

substituting values

         \eta _a  =  \frac{63000}{1.37*10^{5}}

         \eta _a  = 0.46

     

7 0
3 years ago
NASA developed a reflective foil barrier to help shield spacecraft from heat transfer in space. These reflective barriers are no
morpeh [17]

Answer: Radiation

Explanation: Radiation is the energy that comes from a source in form of electromagnetic waves, subatomic particles, light, or heat which travels through space.

Examples of radiation include the light, heat, and particles emitted from the Sun.

Using a foil barrier to prevent heat transfer is possible because foil has a silver color, and silver reflects light and heat instead of absorbing them. This is the opposite of black surfaces that absorb heat.

So in homes where these foil reflective barriers are used, the transfer of heat through Radiation is highly reduced.

3 0
3 years ago
the specific heat of water is 4.2 j/c. if it takes 31,500 joules to heat to warm 750 g of water, what was the temperature change
defon
The amount of heat needed to increase the temperature of a substance by \Delta T is given by
Q=mC_s \Delta T
where
m is the mass of the substance
C_s the specific heat capacity
\Delta T the increase in temperature

In our problem, the mass of the water is m=750 g, the specific heat is C_s = 4.2 J/g ^{\circ}C and the amount of heat supplied is Q=31500 J, so if we re-arrange the previous formula we find the increase in temperature of the water:
\Delta T= \frac{Q}{m C_s}= \frac{31500 J}{(750 g)(4.20 J/g^{\circ} C)}=10^{\circ}C
7 0
3 years ago
Which disease do you think is most easily spread? 5 Answers
Anika [276]

Answer:

coronavirus

sida

tuberculosis

sifilis

epatitis

Explanation:

7 0
3 years ago
If are spaced closely together on the map,there is a drastic temperature change over the distance
AlexFokin [52]

If <em>the isotherms</em> are spaced closely together over some portion of the map, there is a drastic temperature change over that portion.

6 0
3 years ago
Read 2 more answers
Other questions:
  • A 7.0-kilogram cart, A, and a 3.0-kilogram cart, B, are initially held together at rest on a horizontal, frictionless surface. W
    7·1 answer
  • The velocity of a wave is the product of the frequency and the
    13·2 answers
  • where F is the magnitude of the gravitational attraction on either body, m1 and m2 are the masses of the bodies, r is the distan
    5·1 answer
  • What does it mean when there is a curved line going upwards on a graph?<br><br>science 8th grade :)
    10·1 answer
  • Which of the following is equivalent to 2,100 grams?
    7·2 answers
  • A block with mass m =7.4 kg is hung from a vertical spring. when the mass hangs in equilibrium, the spring stretches x = 0.22 m.
    8·1 answer
  • Do the same molecules have to be present on both sides of a chemical equation?<br> why or why not?
    5·1 answer
  • Carlos uses a rope to pull his car 30 m to a parking lot because it ran out of gas
    14·1 answer
  • una onda longitudinal tiene una frecuencia de 200 hz y una longitud de onda de 4.2m ¿cual es la rapidez de la onda?​
    9·1 answer
  • Acceleration is the rate at which what happens?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!