Unit 10 Thermal Energy

Which of the following is a direct cause of a substance's temperature increase?

Kinetic energy is added to the particles of the substance.

As the temperature of a substance increases, its volume tends to

increase

If two small beakers of water, one at 70 C and one at 80 C, are emptied into a large beaker, what

The final temperature is between 70 C and 80 C

Energy transferred as heat occurs between two bodies in thermal contact when they differ in

temperature

Heat is the ________.

transfer of thermal energy

Internal energy is the ________.

total amount of energy contained in an object

The fact that desert sand is very hot in the day and very cold at night is evidence that sand has a

low specific heat capacity

If the specific heat capacity of water were higher than it is, lakes would be

less likely to freeze

A piece of iron (c = 444 J/g C) and a cup of water (c=4.186 J/g C) both have the same temperature... energy of each doubles ________.

the iron will have the higher temperature

Plastic foam is a good heat

insulator

Heat travels from the sun to Earth by

radiation

Energy transfer by convection is primarily restricted to

fluids.

Which cools at the faster rate, a pot of boiling water left at room temperature or a pot of lukewarm water... temperature?

The boiling water.

A piece of metal will feel colder than a piece of wood at the same temperature. Why?

Metals, in general, are good heat conductors.

If 200 grams of water is to be heated from 24.0 degrees C to 100 degrees C to make a cup of... c=4.18 j/gC

63,536 J

How many grams of water would require 2200 joules of heat to raise its temperature from 34... 4.184 J/gC

7.974 g

_____________is defined as average kinetic energy

temperature

The sum of kinetic energy and potential energy is ________________.

total mechanical energy

measure of the amount of heat it takes to change the temperature of an object is its _______.

specific heat capacity

A measure of how easily an object gains or loses heat is its __________

thermal conductivity

Define the three different types of heat: conduction, convection, and radiation. Give an example of each.

Conduction: Direct contact, like a metal spoon in hot soup.

Convection: Movement of fluids, like boiling water.

Radiation: Electromagnetic waves, like warmth from the sun.

A 2.50 g sample of zinc is heated., then placed in a calorimeter containing 65.0 g of water. Temperature of water is 20.00 oC to 22.50 oC. The specific heat of zinc is 390 J/KgoC. What was the initial temperature of the zinc... temperatures of zinc and water are the same?

-678 degrees C or Q= 65.0(4.18)(22.50-20.00)= 679.25, Ti= (679.25/(2.50)(0.390)+22.50= 718.65 degrees C

A 97.5 g sample of the metal pipe at 100.0 C is placed in a water calorimeter (Cw - 4.184 J/g C) containing 10... is the specific heat capacity of the metal if the calorimeter's final temperature was 30.5 C?

-186 J/g degrees C or Q= 100(4.184)(30.5-25.0)= 2301.2, c= 2301.2/(97.5)(100.0-30.5)= 0.34 J/g degrees C

Covert 75.6 degrees Fahrenheit to Celsius.

C= (F-32)(5/9), C= (75.6-32)(5/9)= 24.2 degrees C