Chapter 10: Transfer Of Heat Energy And Its Effects

Question 1

Define temperature.

What is the SI unit of temperature?

Answer 1

Temperature is the measure of how hot an object is.

Question 2

Additional info you need to know

Answer 2

When 2 objects are in contact, heat is always transferred from the hotter object to the colder object. The temp of the colder object increases while the temp of the hotter object decreases until the two objects reach the [same temperature].

When a substance is heated, it [gains heat] and [expands]. When a substance is cooled, it [releases heat] and [contracts].

Expansion and contraction can take place in solids, liquids AND GASES.

Question 3

Bimetallic strip:

Brass expands more/less than steel and contracts more/less than steel.

Answer 3

Answer for both is ‘more’

Question 4

Why do hot air balloons rise when the air inside it is heated?

Answer 4

When the air inside a balloon is heated, it [expands] and [inflates] the balloon. Since the heated air [inside the balloon] is [less dense] than the air [outside the balloon], it causes the balloon to rise.

Question 5

What are the ways in which heat energy can be transferred from one place to another?

Answer 5

-Conduction
-Convection
-Radiation

Question 6

Define conduction

Answer 6

Conduction is the transfer of heat energy [without] the [physical movement] of the medium.

Question 7

(Conduction occurs in solids, liquids AND GASES)

Explain how conduction works.