Click to Chat

0120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: R

There are no items in this cart.
Continue Shopping
Get instant 20% OFF on Online Material.
coupon code: MOB20 | View Course list

• Complete Physics Course - Class 11
• OFFERED PRICE: R 2,800
• View Details
Get extra R 700 off
USE CODE: SSPD25

				   Can anyone explain briefly explain about the NEWTONS METHOD OF COOLING and WEINS DISPLACEMENT...??


6 years ago

Share

										Dear Pradeep,
Newton's method of cooling explains the rate of cooling of a substance when it is placed in the surroundings having a temperature lower than its own temperature. It can be derived from stefan boltzmann law of radiation of energy. i.e. it radiates more energy than it receives.. hence, its temperature drops.
Newton's law of cooling, states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings. The law is
$\frac{d Q}{d t} = h \cdot A( T_{\text{env}}- T(t)) = - h \cdot A \Delta T(t)\quad$ Q = Thermal energy in joulesh = heat transfer coefficientA = Surface area of the heat being transferredT = Temperature of the object's surface and interior (since these are the same in this approximation)Tenv = Temperature of the environmentΔT(t) = T(t) − Tenv is the time-dependent thermal gradient between environment and objectNow, for wein's displacement law, it says that, radiation is emitted by any black body in the form of combination of many electromagnetic waves, i.e. the radiation consists of many wavelengths out of which one wavelength has a maximum intensity. This maximum wavelength is inversely proportional to Temperature, i.e. higher temperature => higher energy => lower wavelength.$\lambda_{\mathrm{max}} = \frac{b}{T}$

Where
$\lambda_{\mathrm{max}}\!$ is the wavelength of peak intensity in meters;$T\!$ is the temperature of the blackbody in kelvin;$b\!$ is a constant of proportionality called Wien's displacement constant and is equal to 2.8977685(51)×10−3 m·K
Please feel free to post as many doubts on our discussion forum as you can. If you find any question Difficult to understand - post it here and we will get you the answer and detailed solution very quickly. We are all IITians and here to help you in your IIT JEE preparation. All the best pradeep !!!Regards,Askiitians Experts
Rohith Gandhi P


6 years ago
										λDear Pradeep,
To explain the Newtons law in a precise u can conduct  a simple experiment. Take hot coffee in a cup and measure its temperature. Now after some time again take the measurement and continue the coffee  to cool again. After making such measurements untillthe cofee reaches the room temperature, we notice that the cooling was fast when the temperature difference between the coffee and the surroundings is high and as the temperature difference decreases then the time of cooling increases.
Rate of cooling is nothing but rate of heat transfer is directly realated to the temperature difference between the substance to be cooled and the surroundings.
Also instead of conducting the experiment in a cup if do it in a plate which has larger surface area then this rate even increases more. Thus, we can  write a relation between these factors with a constant called heat transfer coefficient we get a relation as shown in the figure
Veins Displacement law:
To know about this law we have to study about black body radiations emitted. The black bodies are the objects that can absorb all kinds of radiations incident on it and can emit all kinds of radiations. At a given temperature it cannot emit a paticular wavelenth it would emit a broad band of wavelengths that show a peak in the intensity distribution at certaian wavelength λmax.
λmax= b/T
Where λmax=  the wavelength of peak intensity
b = constant of proportionality,
T = Temperature of the black body
This value decreses as the temperature of the black body decreses signifying that at higher temperatures the peak emission wavelength decreases i.e., peak shits towards left signifying the emission of more energetic radiations.  This is also shown in the figure below the first figure.
Please feel free to post as many doubts on our discussion forum as you can. If you find any question Difficult to understand - post it here and we will get you the answer and detailed solution very quickly. We are all IITians and here to help you in your IIT JEE preparation.
All the best  !!!

Regards,


6 years ago

# Other Related Questions on Thermal Physics

What is latent of heat of fusion?

The ' enthalpy' of fusion is a latent heat , because during melting the introduction of heat cannot be observed as a temperature change, as the temperature remains constant during the...

 venky one year ago

The ' enthalpy' of fusion is a latent heat , because during melting the introduction of heat cannot be observed as a temperature change, as the temperature remains constant during the...

 pa1 one year ago
Explain in which cases Power will become Negative in Physics and also in Chemistry?

Dear student The question is not clear...can you please tell in which regard are you asking the poer to be negative?

 Bhavya one month ago

Energy is Negative of a system when that system is isolated from any other system and there is no any other +ve or -ve enery in or out the System to make it +ve.This energy is dangerous as...

 Kuldeep Pal one month ago

@ ramya actually its just the magnitude of work done in unit time . and REMEMBER 1 THING – POWER CANNOT BE -VE . its actually a modulus , so, power can never be -ve . HOPE IT CLEARS YOUR...

 Umakant biswal one month ago
What is overtone?explain 1 st ,2nd and 3 rd overtones???????????????????????

Gowri sankar, An over tone is any frequency higher than the fundamental frequency of a sound.Using the model of Fourier analysis the fundamental and the overtones together are called...

 SAI SARDAR 9 months ago

Dear Gowri Shankar A over tone is any frequency higher than the fundamental frequency of a sound.Using the model of Fourier analysis the fundamental and the overtones together are called...

 Prabhakar ch 9 months ago

A over tone is a partial that can either a harmonic partial other than the fundamental or an inharmonic partial.a harmonic partial is an integral of fundamental frequency.

 N JYOTHEESWAR 9 months ago
what is a magnet and uses explain

Magnets are also used in other types of fastening devices, such as the magnetic base, the magnetic clamp and the refrigerator magnet . Compasses: A compass (or mariner's compass) is a...

 SHANMUKESHWAR one year ago

A magnet (from Greek μαγνήτις λίθος magnḗtis líthos , " Magnesian stone") is a material or object that produces a magnetic field . This magnetic field is invisible but is responsible for...

 RAKESH CHINDAM one year ago

Magnets are also used in other types of fastening devices, such as the magnetic base, the magnetic clamp and the refrigerator magnet. Compasses: A compass (or mariner`s compass) is a...

 L GOUSE BASHA one year ago
A 20g bullet moving at 30m/s stops after penetrating 3 cm bone . Calculate the average force exerted by the bullet .

Time= distance/velocity= 3/(100)*(30)= 1/1000s. Force= mass*acceleration= 20/1000 * 30/1/1000 therefore, force= 20/1000 * 30000= 600Newton.

 Digpal singh 2 months ago
View all Questions »

• Complete Physics Course - Class 12
• OFFERED PRICE: R 2,600
• View Details
Get extra R 650 off
USE CODE: SSPD25

• Complete Physics Course - Class 11
• OFFERED PRICE: R 2,800
• View Details

Get extra R 700 off
USE CODE: SSPD25

More Questions On Thermal Physics