(experiment)Chapter 7:heat

• THIS EXPERIMENT IS TO SHOW THAT THE SUN GIVES OUT HEAT.

• THE PAPER CATCHES FIRE.• THE CONCLUSION IS SUN GIVES OUT

HEAT

• THIS EXPERIMENT IS TO SHOW THAT HEAT CAN BE PRODUCED WHEN THERE IS FRICTION BETWEEN TO OBJECTS.

• BOTH THE STICK AND THE ROCK PRODUCES HEAT AS THERE WERE FRICTION BETWEEN THEM.

RUBBING TWO STICKSSTRIKING TWO STONES

• THIS EXPERIMENT IS TO SHOW THAT HEAT CAUSES SOLID TO EXPAND AND CONTRACTS.

• THE METAL RING EXPANDS WHEN HEATED AND CONTRACTS WHEN COOLED.

• THE METAL RING CAN’T PASS THROUGH THE RING WHEN HEATED AND CAN PASS THROUGH IT AGAIN WHEN IT IS COOLED.

• THE CONCLUSION IS SOLIDS EXPANDS AND CONTRACTS WHEN HEATED AND COOLED

• AFTER FEW MINUTES,THE LIQUID/INDICATOR GOES DOWN BACK AS IT LOOSES HEAT.

• THE CONCLUSION OF THIS EXPERIMENT IS AIR EXPANDS WHEN IS CONTACT WITH HEAT AND CONTRACTS WHEN LOOSES HEAT.

• THIS EXPERIMENT IS TO SHOW THAT HEAT FLOWS BY CONDUCTION.

• THUMBTACK ______ WILL FALL FIRST BECAUSE HEAT FLOWS FROM THE HOT END OF THE IRON ROD TO THE COLD END.

THE PICTURE ABOVE SHOWS HOW HEAT FLOWS BY CONVECTION IN A

LIQUID

THE IMAGE ABOVE SHOWS HOW A VACUMM LOOKS LIKE….

HEAT TRAVELS THOUGH VACUM AS RADIATION OR HEAT RAYS

RADIATION = VACUUM

PAPER COTTON ALUMINIUM FOIL SHEEP WOOL0

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RATE OF HEAT INSULATORS

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• DARK, DULL OBJECTS ABSORB HEAT BETTER THAN WHITE, SHINY OBJECTS.

• DARK, DULL OBJECTS GIVE OUT HEAT BETTER THAN WHITE, SHINY OBJECTS.

1)WHAT IS THE CHANGES IN STATE OF MATTER OCCURS DURING THE MELTING PROCESS?2)WHY IS MERCURY USED IN A THERMOMETER?3)AN OBJECT THAT IS A GOOD ABSORBER OF HEAT HAS A SURFACE CONDITION THAT IS ?4)WHAT IS THE SI UNIT OF HEAT?5)WHAT IS THE SI UNIT OF TEMPERATURE?

QUESTIONS BY US

LOGIC QUESTION BY STUDENTS & TEACHER