Physics-heat transfers,conduction,insulation,Specfic heat capacity and energy demands,issues,and imapct on the enviroment

Question 1

Define

Heat

Answer 1

The form of energy that is transferred between two substances at different temperatures.

The direction of energy flow is from the substance of higher temperature

Heat is measured in units of energy, usually calories or joules.

Question 2

Define

Temperature

Answer 2

The measure of hotness or coldness expressed in units including Celsius,Farenheit and Kelvin.

Temperature indicates the direction in which heat energy will flow

i.e. From a hotter body (one at a higher temperature) to a colder body (one at a lower temperature).

Question 3

Define

Conduction

Answer 3

The transfer of energy in the form of heat or electricity from one atom to another in an object due to direct contact.

An object which does this well is called a conductor

Conduction of heat happens when molecules vibrate due to an increase in temperature, which passes the heat energy to the surrounding molecules.

Question 4

Define

Convection

Answer 4

The process of transferring heat through air or liquid currents. Convection causes liquid or gas to heat up, expand, and decrease in density. This causes movement of the liquid or gas in a convection current.

Convection causes liquid or gas to heat up and change density

This causes movement of the liquid or gas in a convection current.

Question 5

Define

Radiation

Answer 5

Energy that moves from one place to another in a form that can be described as waves or particles.

We are exposed to radiation in our everyday life.

Question 6

Define

Insulation/Insulator

Answer 6

Insulation:The act of making a conductor an insulator
Insulator:A material that is poor at conducting heat or electricity

Question 7

Define

Specfic heat capacity

Answer 7

The amount of heat that needs to be supplied in order to raise the unit mass of substance by 1 degree Celsius

Eg:Amount of joules required to raise the temp of a kilogram of steel by 1 degree celsuis

Question 8

Unit

Specfic heat capacity

Metric

Answer 8

J/(kg°C)

Question 9

Formula

Relating to specfic heat capacity

Answer 9

△E = m * c * △T

NOTE: △T is the same as △θ

Where Change in heat(Joules) = mass(KG) * specfic heat capacity(J/(kg°C)) * temp rise(°C)

Question 10

Highest SHC

Answer 10

Liquid water(Hydrogen)

Question 11

Lowest SHC

Answer 11

Radon

Question 12

Define

Energy demand

Answer 12

How much energy (some) humans want to consume at any given time in a particular timeframe

Eg:Tokyo energy demand for tomorrow may be predicted to be 50MJ