energy and temperature

Question 1

Give 4 ways of transferring energy between stores

Answer 1

1- Radiation ( like light)
2- Electrical current
3- Waves ( sound)
4- Heat

Question 2

Draw energy transfer diagrams for these three examples and highlight the ‘waste’ energy.

1- Light bulb
2- TV
3- Radiator

Answer 2

1- Chemical –> Light + Heat
waste: heat

2- Electrical—> Light+Sound + Heat
waste: heat

3- Electrical –> Light+ Sound+ Heat
waste: Light and sound

Question 3

What is temperature

Answer 3

Temperature is a measure of how hot or cold something is

Question 4

What do u use to measure temperature

Answer 4

thermometer

Question 5

What is temperature measured in

Answer 5

Degrees celcuis

Question 6

Describe the difference between energy and temperature

Answer 6

Energy depends on the amount of material you have, however temperature doesn’t depend on the amount of material you have.

Question 7

Which has a bigger thermal store of energy ?
1- Swimming pool at 50 degrees celcuis or a beaker with water at 50 degrees celcuis?

Answer 7

1- Swimming pool at 50 degrees celcuis

Question 8

Draw 3 boxes in you books as shown below.
In each one draw how particles are arranged in solids, liquids and gases.

Answer 8

( check)

Question 9

Describe the arrangement and movement of particles in solids.

Answer 9

Arranged: Fixed pattern.
Touch their neighbour
Movement: Vibrate on the spot.
- Don’t move
- Don’t flow
- Can’t be compressed

Question 10

Describe the arrangement and movement of particles in liquids.

Answer 10

Arrangement: -No fixed shape
- Touch their neighbour.
Movement: - Slide over each other.
- Flow
- Can’t be compressed

Question 11

Describe the arrangement and movement of particles in gases.

Answer 11

Arranged: - Spread out
Movement: Move freely on all direction
-Can flow
- Can be compressed

Question 12

What happens to the particles you heat them ( solid, liquid and gas)

Answer 12

When you heat objects, the particle’s movement changes. Solids vibrate more and liquids and gases move faster and vibrate more.

Question 13

What does the energy you need to increase the temperature dependent on?

Answer 13

1- Mass of the material
2- What the material is made up
3- The temperature rise that you want.

Question 14

Define equilibrium

Answer 14

When both objects are at the same temperature, it is at equilibrium

Question 15

Does temperature go from hot to cold or from cold to hot

Answer 15

hot to cold

Question 16

What happens to get the objects temperature at equilbruim

Answer 16

The temperature difference decreases until they are at equilbruim

Question 17

Describe the energy transfer between stores once objects are equilbrium

Answer 17

There is no transfer between energy stores once objects are at equilbrium.

Question 18

Describe how and why the temperature of the juice will change if left in a room at 20 degrees Celsius.

Answer 18

The temperature of the juice is colder than the temperature of the air in the room. The temperature of the air in the room is warmer than the tempertaure of the juice Temperature always goes from hot to cold so there is a flow of heat energy from the air in the room to the juice. The difference in temperature decrease until they are thermal equilubruim. The temperature of the room will go down and the temperture of the juice will go up.

Question 19

Explain why the snowman melts. (4 marks)

Answer 19

Temperature is a measure of how fast each particles move when heated. When the snowman is heated, the particles move faster ( gain more kinetic energy) and vibrate more. The bonds then weaken melting the ice. The temperature of the snowman is colder than the temperature of the air around it. So, there is a flow of heat energy from the air in the room to the snowman. The temperature difference decrease until the snowman melts so the air of the room and the melted snowman are at thermal equilibrium. Temperature only ever moves from hot objects to cold objects so the heat energy transfer is from the air in the room to the snowman causing it to heat and melt.

Question 20

complete the sentences below.
You measure ___________ in degrees Celsius using a ___________. __________ does not depend on the amount of material that you have, but the ___________ stored does. The particles in a ____________ vibrate more when you heat the solid. Energy moves from hotter objects to colder objects unit they are in ___________. (6 marks)

Answer 20

1 temperature, thermometer, temperature, energy, solids, equilibrium

Question 21

2. Sort these things in order from least energy stored to most energy stored: a saucepan full of water at 50°c, a cup of water at 30 °c, a saucepan full of water at 30 °c. Explain your order. (3 marks)

Answer 21

2 a cup of water at 30\deg C, a saucepan of water at 30\deg C, a saucepan of water at 50\deg C

Question 22

CHALLENGE: You are cooking a pizza. You place your pizza on a metal tray at room temperature and put it in the oven. When the pizza is cooked you remove the tray from the oven. Eventually it reaches room temperature again. Describe and explain in detail what happens to the motion of the particles in the metal tray. (6 marks)

Answer 22

The particles in the metal tray vibrate. The hotter the tray the more they vibrate. When the tray goes into the oven the metal heats up. The particles on the outside of the tray vibrate more. They pass the vibrations on. The tray reaches the same temperature as the inside of the oven. The tray is in equilibrium. When you take the tray out of the oven it cools down. The energy moves from the thermal store of the tray to the thermal store of the air. The air heats up. The tray reaches the same temperature as the air. The particles in the tray vibrate less.

Question 23

Explain the difference in particle movement when solids are heated

Answer 23

1- Solids vibrate in their place more until enough heat energy is transferred from it’s surround to flow over each other (melting)

Question 24

Explain the difference in particle movement when liquids are heated

Answer 24

liquids move faster until enough energy is transfeered from it’s surround it to escape from each other ( boiling).

Question 25

Explain the difference in particle movement when gas are heated

Answer 25

The particles move faster