Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is the difference between temperature and heat? |
Temperature = how hot something is, measured in Celsius °c Heat= a form of energy, measured in Joules (J) |
The hotter something is the more heat ..... It has |
|
|
Why will a hot drink cool down, and how long for? |
A hot drink will cool because energy is transferred from it to its surroundings. It will cool until it is the same temperature as it's surroundings |
|
|
|
What affects the the rate of energy being transferred between objects? |
The difference in temperature When the difference is greater the rate is higher |
|
|
|
What does a thermogram do? |
Used to show how hot an object is by creating a picture where different temperatures are different colours |
|
|
|
What colours are the hottest/ coolest in a thermogram? |
Hottest = white ( then red yellow etc) Coolest = dark blue (then light blue green etc) |
|
|
|
What is temperature in terms of energy and particles? |
A measure of the average kinetic energy of the particles in a substance |
Ake Of the Pias |
|
|
What is specific heat capacity? |
The value of how much energy an object can hold |
V of hme an och |
|
|
What is the specific heat capacity of water? |
4200 |
|
|
|
What is the formula to calculate the amount of energy needed to heat an object? |
|
E = m x spc x tc |
|
|
Name some practical uses of light and lasers |
-surgery and dental treatment -cutting materials and industry -weapon guidance -laser light show |
S C W L |
|
|
What does a laser produce? |
A narrow monochromatic beam of light. |
|
|
|
Why do most lasers proxy d an intense coherent beam of light? |
-waves havd the same frequency -waves are in phase with each other -waves havd low divergence |
F P D |
|
|
How is a laser beam used om a CD player? |
-information is stored on the bottom surface -information is stored digitally -information im the form of patterns of bumps (known as pits) -a cd will contain billions of pits |
|
|
|
How does a microwave oven work? |
Microwaved cause heating when absorbed by water |
|
|
|
What are the properties of infrared radiation? |
-heats the surface of food -is reflected by shiny surfaces |
|
|
|
What are the properties of microwaves? |
-penetrate 1cm into food -are reflected by shiny metal surfaces -can cause burns when absorbed by body tissue -pass through glass and plastics |
|
|
|
How are microwaves and infrared transfered to materials? |
-infrared is absorbed by only particles on the surface increasing their KE -KE is transferred to the centre of the food by conduction or convection. -microwaves are absorbed by only water and fat particles in the outer layers increasing their KE |
|
|
|
What kind of signals do movie phones use? |
-Microwaves |
|
|
|
Why does signal loss with microwaves happen? |
-adverse weather and large areas of surface water scatter signals. -loss of line of sight did go curvature of the earth -no diffraction of microwaves around large objects -interference between signals |
|
|
|
Describe how the problems of signal loss are reduced? |
-limiting the distance between transmitters -high positioning of transmitters |
|
