Chapter 10- Transfer of Heat and its Effects

Question 1

SI Unit of Temperature

Answer 1

K

Question 2

How does heat transfer work

Answer 2

Heat is transferred from the hotter object to the colder object until both of them reaches the same temperature

Question 3

Define expansion

Answer 3

When an object gains heat and increases in volume

Question 4

Define contraction

Answer 4

When an object loses heat and reduces in volume

Question 5

Left space in certain places in the world (e.g.railroads) because of?

Answer 5

Expansion and the chance for train racks to buckle

Question 6

Usages of bimetallic strips

Answer 6

1)Thermostat
2)fire alarm
3)Oven

Question 7

How does bimetallic strips work (in general)

Answer 7

In the bimetallic strip, the brass side will expand more than the steel side. This causes an open circuit, switching off whatever the bimetallic strip is connected to. When the bimetallic strip cools down, it will become straight again and allow the contacts to touch for a closed circuit.

Question 8

How does the bimetallic strip work in a food thermometer?

Answer 8

One end of nthe bimetaqllic strip will be attached to a pivot or fixed end, and the other point will have a pointer connected to it. Due to the different expansion rates of the metals, it will cause the coil to unwind or tighten, allowing the pointer to move appropraitely on a scale.

Question 9

How does liquid in glass thermometers work

Answer 9

When the bulb of a thermometer gains heat, the liquid inside will expand more than the glass, causing the liquid to rise up in the thermometer

Question 10

How do hot air balloons work

Answer 10

Since the air in the balloon is heated, its volume increases, but the mass of the air does not change due to conservation of mass, leading the hot air balloon to be less dense than the air and rise

Question 11

Which states of matter can perform conduction, and which state of matter performs it best

Answer 11

All 3. Solid.

Question 12

Define conduction

Answer 12

Conduction is the transfer of heat through contact, without the physical movement of the medium

Question 13

Why does it feel colder when you touch a metal can then a milk carton although they are at the same temperature

Answer 13

This is due to the fact that the metal can is a better conductor of heat, thereby allowing more heat to be transferred from our hands at a faster rate

Question 14

Which type of solid is the best conductor of heat

Answer 14

metals

Question 15

Why are solids generally better conductors of heat then liquids

Answer 15

This is due to the fact that the particles are arranged more closely to one another, allowing heat transfer to happen more quickly

Question 16

Define convection

Answer 16

Convection is the transfer of heat from one place to another through the physical movement of a medium

Question 17

In which states of matter can convection be effective in

Answer 17

Fluids (liquids and gasses)

Question 18

How does a bunsen beaker perform convection

Answer 18

Particles of water get heated by the flame through conduction. Particles gain TE, leading to greater distances between particles. This will induce the increase in volume but conservation of mass, leading the water to be less dense and rise to the top, while causing the cool and denser air at the top to then sink. The air is denser at the top as heat has not reached it yet. leading it to sink to the bottom, thus forming a convection current. Convection will occur until the temperature throughout the water is equal

SAME EXPLANATION FOR AIR

Question 19

How does the sun transfer heat to earth

Answer 19

Through radiation

Question 20

What is the greenhouse effect.

Answer 20

When greenhouse gasses trap heat in the atmosphere of earth to support life

Question 21

What are factors affecting the rate of conduction

Answer 21

The level of how well an object conducts heat

Question 22

What are factors that affect radiation

Answer 22

1) Temperature of Object (higher temperature euqates to higher radiation)
2) Surface area of object (larger surface area leads to higher rate of radiation)

Question 23

What are black, dull materials good for in terms of radiation

Answer 23

Absorption of radiation and emission of radiation

Question 24

What are white shiny objects poor in in terms of radiation

Answer 24

Absorption and radiation

Question 25

How do sea breezes occur

Answer 25

IN DAY When the sun heats up the land, it well make the air on top of it hotter as well, causing it to expand due to faster moving particles and lower FOA. This causes the density of the air above the land to decrease, and cool down above the sea. Then it moves back onto land and the cycle occurs again.

Question 26

How do land breezes occur

Answer 26

AT NIGHT When the layer of air above the sea is warmer, it will become less dense and rise due to expansion, which resulted from faster particles and weaker FOA. This air will then cool above land and move back into the warmer ocean, forming a convection cycle