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WorksheetsScience Study Guide: Thermal Energy/Heat 9th Grade
Total questions: 25
Worksheet time: 13mins
A new type of oven that cooks food quickly and more completely is the convection oven. The key difference in this type of oven and a regular oven is that it. . .
circulates the hot air.
cooks at higher temperatures.
irradiates the food at the same time.
sends heat from the inside of the food to the outside.
Substance Specific Heat (J kg-1 K-1)
Aluminum 900
Copper 390
Brass 380
Silver 230
Platinum 130
Explain why a Chef in a very busy restaurant would prefer a copper pot over an aluminum pot.
The copper pot would heat faster because it has a lower specific heat value.
The copper pot would heat slower because it has a lower specific heat value.
The copper pot would heat faster because it has a higher specific heat value.
The copper pot would heat slower because it has a higher specific heat value.
Substance Specific Heat (J kg-1 K-1)
Aluminum 900
Copper 390
Brass 380
Silver 230
Platinum 130
If 130 J of energy were added to 1 kg of each of these samples, which would experience the GREATEST temperature increase?
Aluminum
Brass
Copper
Platinum
Which diagram BEST represents a convection heating current?
Substance Specific Heat (J kg-1 K-1)
Aluminum 900
Copper 390
Brass 380
Silver 230
Platinum 130
Five metal samples, with equal masses, are heated to 200oC. Each solid is dropped into a beaker containing 200 ml 15oC water. Which metal will raise the temperature of the water the most?
aluminum
copper
gold
platinum
Substance Number or Calories of Heat
1 80
2 0
The substances in the table are combined, and Substance 1 loses 40 calories of heat. How many calories of heat will Substance 2 eventually gain?
0
20
40
80
A metal ball of mass 100 g is heated to 90°C and then cooled to 25°C. The heat lost in the process is 2.5 kJ. Another metal ball of mass 200 g is heated to 90°C and then cooled to 25°C. The heat lost in the process is 5.0 kJ. What can be concluded from the data?
The balls are made of the same material.
The first ball is made of a material with a higher specific heat.
The second ball is made of a material with a higher specific heat.
The specific heat of one of the balls is two times that of the other.
Change in Temperature
Temperature light on °C Temperature light off °C
Time
(min) Sand Water Time
(min) Sand Water
Start 22 22 Start 58 30
1 26 24 1 52 30
5 36 26 5 46 30
10 44 28 10 36 28
15 58 30 15 26 26
Josh did an experiment recording the changes in temperature in sand and water when exposed to a light source, and then when the light source was removed. Josh noticed that the sand heated up faster than the water and then cools faster than the water. Josh concludes that. . .
sand is the better insulator.
water is the better conductor.
water is the better insulator.
sand has a higher heat capacity.
Two identical pots, one black and one silver, containing exactly the same amounts of water, are heated to the same temperature. They are left uncovered and placed in the same room. After 15 minutes the water in the black pot is significantly cooler than the water in the silver pot. Which of these statements best explains this difference?
The black pot emits heat at a faster rate than the silver pot.
The black pot allows more heat to be lost through evaporation.
The silver pot absorbs heat from the surroundings in the room.
The silver pot reflects heat into the water and keeps it warm longer.
Burning logs in the fireplace produce heat energy. The dog gets warm from the fire when heat energy is transferred by. . .
the air.
radiation.
conduction.
the flames.
A cup of hot water cannot melt a large block of ice. However, the same block melts when dropped into a lake. This is because. . .
the lake is at a lower temperature than the cup of hot water.
the lake is at a higher temperature than the cup of hot water.
the lake contains less mass and heat than the cup of hot water.
the lake contains more mass and more heat than the cup of hot water.
A 1-kg iron frying pan is placed on a stove. The pan increases from 20°C to 250°C. If the same amount of heat is added to a pan with a greater specific heat, what can you predict about the temperature of this second pan?
The second pan would reach a lower temperature.
The second pan would reach a higher temperature.
The second pan would reach the same temperature.
No conclusion can be made from this information.
Based on the principles of convection, conduction and thermal radiation, which scenario below is most similar to the following situation? You put a heating pad on your back after exercising.
Feeling a metal wire get warmer as you roast a marshmallow over a fire.
Warm air rising in a room where the air is moving.
The sun warming up the roof on a house.
Cold water sinking in a pot of water being warmed up on the stove.
Which image exclusively represents the principle of radiation?
IV
III
II
I
Use the concept of specific heat to analyze the following observation.
Two pieces of metal with exactly the same mass are placed on a surface in bright sunlight. The temperature of the 1st block increases by 3°C while the temperature of the 2ndincreases by 8°C. If the specific heat of the 2nd block is 0.24 J/g-K, what is the specific heat of the 1st block?
0.3 J/g-K
0.64 J/g-K
1.2 J/g-K
1.56 J/g-K
Determine which heat transfers below are due to the process of conduction.
I) You walk barefoot on the hot street and it burns your toes.
II) When you get into a car with hot black leather in the middle of the summer and your skin
starts to get burned.
III) A flame heats the air inside a hot air balloon and the balloon rises.
IV) A boy sits to the side of a campfire. He is 10 feet away, but still feels warm.
I and II
III and IV
I, II, and IV
II, III, and IV
What type of heat transfer is used in a restaurant that uses ovens with fans inside? Justify your answer.
It is conduction because the food must be in the oven.
It is conduction because the oven is hotter than the food.
It is convection because air is circulated to help cook the food.
It is convection because you feel the heat from a few inches away from the pan.
Two liquids that are at different temperatures are added to each other in a container and then the container is closed. The temperature is taken at one-minute intervals. Which graph shows the correct change in temperature for the liquids over the next 7 minutes?
Graph A
Graph B
Graph C
Graph D
Two objects that are at different temperatures are added to a container of water and then the container is closed. The temperature is taken at one-minute intervals. The graph shows the change in temperature for the objects over the next 7 minutes. Which statement is correct?
The objects are different in mass.
The water has more mass than both objects.
The water started lower than 40oC.
The water released energy into the objects.
Heat capacity is an intrinsic physical property of a substance that measures the amount of heat required to change that substance’s temperature by a given amount. The specific heat is the amount of heat necessary to change the temperature of 1.00 kg of mass by 1.00oC. Its SI unit is J/(kg⋅K) or J/(kg⋅C).
Copper is a good conductor of heat while water is not. What statements apply to copper's ability to conduct heat? Choose ALL that apply.
Copper is a solid.
Copper is a metal.
Copper has a low specific heat.
Copper readily absorbs heat energy.
Copper takes time to absorb heat energy.
A total of 54.0 calories of heat are absorbed as 58.3 g of lead is heated from 12.0° C to 42.0° C. What is the specific heat of lead?
0.029cal gram °C
0.022cal gram °C
0.017cal gram °C
0.031cal gram °C
During the day, the temperature of the sand in a desert rises as the sand is heated by the sun. After the sun sets, the sand cools. What happens to the heat energy in the sand as it cools?
It is destroyed.
It is used by the sand to do work.
It goes back into the sun, completing the cycle.
It is transferred to the air via the process of radiation
Substance Number of Calories of Heat
1 0
2 100
The substances in the table are combined, and Substance 2 loses 50 calories of heat. How many calories of heat will Substance 1 eventually gain?
10
25
50
100
Why do the inner walls of a vacuum flask have a silver coating?
To stop heat loss by radiation
To reduce heat loss by radiation
To reduce heat loss by conduction
To reduce heat loss by convection
Fiberglass, an insulator, can be found in the walls and roofs of some houses and buildings. Why would an insulator be needed inside of buildings in the winter?
It makes the building look pretty.
It keeps the heat inside of the building.
It keeps the heat outside of the building.
It keeps the cool air inside the building.
