What is heat?, Physics

Assignment Help:

What is Heat?

We now have several scales for measuring temperature, but first let's ask, “Is temperature the same as heat?” If I add heat to a pot of water, the water's temperature will go up. But if I have a small pot of cold water and a large pot of cold water, will their temperatures go up the same amount if I add the same amount of heat to each? No. Heat is more than just the temperature of the material. It also depends on how much of the material there is and what the material is made of.

Kinetic theory of matter proposes that heat is a measure of the internal kinetic energy (microscopic jiggles) of the molecules and atoms making up the substance. If, when I touch a stove, my hand is burned (heat was transferred to my hand), then I can deduce that the temperature (and kinetic energy of the molecules or atoms) of the stove was higher than the temperature (and kinetic energy of the molecules or atoms) of my hand. Temperature indicates when heat will be transferred but does not tell the whole story as to how much heat energy is stored in a substance.

2123_What is Heat 1.png

The specific heat, c,( in cal/gCo) of a material is a number which gives us an idea of how much heat is needed to raise the temperature of one gram of the material one Celsius degree. This is a property of materials which explains why some foods remain hotter longer than others. You are more likely to burn your tongue on the filling of a hot apple pie than the crust. This tells you experimentally that the apple pie filling has a greater specific heat (it takes more heat to bring one gram of it to a given temperature or you must remove more heat to drop the temperature of one gram) than the crust. Water has one of highest specific heats at 1 cal/gCo. One gram of water is able to absorb and hold more heat than other liquids. This is why before the advent of electric blankets and heating pads, the use of hot water bottles was common. It also means that when water is cold, it can absorb more heat as it warms up. This is why we use ice in our coolers to keep our food and drinks cold, and cold water circulating in tubing is often used to cool many things including an astronaut in his/her space suit. This is also the main reason why the outdoor temperature near bodies of water is moderated. It tends to be cooler in summer and warmer in winter near the beach.
 
Example - How much heat must be added to 5.0 kg of water to increase its temperature by 20 Co? (the specific heat of water is 1.0 cal/gCo = 1.0 kcal/kgC°)

1565_What is Heat 3.png

2319_What is Heat 2.png

  
or 100 of the Calories that we speak of when we diet, because one diet Calorie is equal to one kilocalorie.


Related Discussions:- What is heat?

What is photo-conductive cell, It is based on the principle that conductivi...

It is based on the principle that conductivity of a semiconductor enhances with increase in the intensity of incident light. In this, a thin layer of some semiconductor (as

Motion in one dimension, A woman walks 250m in the direction 35 degrees eas...

A woman walks 250m in the direction 35 degrees east of north, then 170m directly east. (a) using graphical method, find her final displacement from the starting point. (b) compare

Eotvos law of capillarity, Eotvos law of capillarity (Baron L. von Eotvos; ...

Eotvos law of capillarity (Baron L. von Eotvos; c. 1870): The surface tension gamma of liquid is associated to its temperature T, the liquid's critical temperature, T*, & its

Curies law, Curie's law (P. Curie) The susceptibility, khi, of an isot...

Curie's law (P. Curie) The susceptibility, khi, of an isotropic paramagnetic substance is associated to its thermodynamic temperature T through the equation khi = C/T

Weight removed from earth and it consequences., With mans lust for the unkn...

With mans lust for the unknown in space exploration, what will happen to our planet by removing so much weight in the form of spacecraft that will never return and can the earth re

The algebra of dimensionality, Rule 1: In order to sum or subtract two phys...

Rule 1: In order to sum or subtract two physical quantities the quantities must have the similar dimension. The final physical quantity has the similar dimensions. Physical quantit

Jet propulsion is made possible by action and reaction, Jet propulsion is m...

Jet propulsion is made possible by action and reaction Fit a small cardboard stabilizer to the neck of a balloon by means of adhesive tape. Inflate the balloon, and close the m

How to find out percentage error, Take the difference among your experiment...

Take the difference among your experimental value and your known value, and divide that difference by your know value. Say you experimentally found the force of gravity to be 8m/s

Define about the graphite structure, Define about the Graphite Structure ...

Define about the Graphite Structure   Graphite is the allotropic form of carbon. In case of graphite the carbon atoms are arranged in regular hexagons in flat parallel layers a

Illustrate the newton s laws of motion, Q. Illustrate the Newton s laws of ...

Q. Illustrate the Newton s laws of motion? Answer:- 1. A body at rest will stay at rest and one in motion will remain in motion until and unless acted upon by an external

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd