physics
8000 Joules of heat are added to 1 kilogram of water when its temperature is 40 degrees Celsius. The resulting temperature of the water is ____.
42 degrees
A Joule is a common unit of force.
false
____________ is a form of energy transfer.
heat
The ideal efficiency for a heat engine operating between temperatures of 2050 K and 310 K is _____
85%
Which temperature scale labels the freezing point of water at 0 degrees?
Celsius
It is possible to wholly convert a given amount of heat energy into mechanical energy.
false
Entropy measures ______.
messiness
Systems that are left alone tend to move toward a state of _____.
more entropy
Specific heat capacity is related to the amount of internal energy ______.
needed to change the temperature of one kilogram of a substance one degree
Systems left alone tend to move to a state of greater entropy
true
A recycling plant manager needs to melt 1500 kg of scrap copper to sell to a wire manufacturer. The copper is at 15°C and its melting point is 1083°C. The copper has a specific heat of 385 J/kgK• . How much heat is required to raise the temperature of the copper to its melting point?
6.2e8J
A 2kg sample of liquid water is heated from 21 to 22 degrees Celsius. The specific heat capacity of water is 4200J/kg*C. How much heat is transferred?
8400 J
A student hypothesizes that the mass of a substance affects how the temperature of the substance changes when it is heated. The student uses the following procedure to test the hypothesis. • Each sample is initially at room temperature before heating. • Each sample is heated for the same amount of time with the same heat source. • The final temperature is measured for each sample. Which of the following would be the best way to select the samples for testing the student's hypothesis?
Obtain samples of one substance, each with a different mass
Ceramic automobile engines that can operate at higher temperatures will be ______
more efficient
The lowest possible temperature is ____.
-273 degrees Celsius
A change in temperature of 10 degrees Celsius is equal to a change of ____
10 K
80 joules of heat are added to a system that performs 55 Joules of work. The internal energy change of the system is _____.
25 J
Mix a liter of 60 degree Celsius water with 2 liters of 40 degree Celsius water and you'll have 3 liters of water at _____.
47 degrees Celsiu
A temperature scale that has 100 degrees between the boiling point and the freezing point of water is the Fahrenheit scale.
False
A heated rock is placed in a container of water that is cooler than room temperature. Which of the following statements best describes what happens?
The heated rock loses heat to the container of water until the rock, the container, and the water all reach the same final temperature.
Heat is measured in _____.
all of these
Temperature is related mostly to the _____.
average molecular kinetic energy in a substance
When mechanical work is done ON A SYSTEM, there can be an increase in its _____
both of the above
The energy content in a piece of food is normally determined by ______.
burning the food
The first law of thermodynamics is a restatement of the _____
conservation of energy
When work is done BY A SYSTEM and no heat is added to it, the temperature of the system ______.
decreases
Heat is the _____.
energy transferred between objects because of a temperature difference
If all the friction could be eliminated in a heat engine, its efficiency would be 100%
false
The total of all energies in a substance is its temperature.
false
The greater the difference in temperature between the input reservoir for a heat engine, the ______.
greater the efficiency
Some molecules are able to absorb large amounts of energy in the form of internal vibrations and rotations. Materials composed of such molecules would have ______.
high specific heat capacities
The largest extremes in temperature are usually experienced _____.
in the middle of a continent
When a volume of air is compressed and no heat enters or leaves, the air temperature will _____
increase
As a system becomes more disordered, entropy ______
increases
Suppose the temperature of the input resevoir in a heat engine doesn't change, and as the sink temperature is lowered, the efficiency of the engine ______.
increases
Heat flows when there
is a temperature difference
If the specific heat capacity of water were higher than it is, lakes would be ______.
less likely to freeze
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
Heat naturally flows from a _________ region to a _________ region
low temperature/high temperature hot/cold
Entropy is closely related to the _____
second law of thermodynamics
Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warm block warms to 25 degrees C. This would violate the ______.
second law of thermodynamics
Measurements inside a sealed container show that the pressure exerted by a gas increases as the thermal energy of the gas increases. Which of the following best explains this pressure increase?
the gas molecules move faster and strike the container walls more frequently.
Which is denser: Ice at 0 degrees Celsius or water at 4 degrees Celsius?
the water
Internal energy is the _____
total amount of energy contained in an object
Efficiency in a heat engine is increased when there is a greater difference in input and output temperatures
true
Heat is the energy that moves from one object to another because of a temperature difference.
true
It is possible to totally convert a given amount of mechanical energy into heat.
true
Liquids usually expand when heated
true
The amount of heat required to change the temperature of a unit mass of a substance by 1 degree is its specific heat capacity.
true
The average kinetic energy of molecules in a substance is related to temperature.
true
When work is done BY A SYSTEM on something else, the temperature of the system decreases.
true
Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses ______.
volume and pressure
Running a refrigerator with its door open in a hot room makes the room _____
warmer
Which has the higher specific heat capacity, water or sand?
water
During a very cold winter, water pipes sometimes burst. The reason for this is _____.
water expands when freezing
The reason an ocean's temperature doesn't vary much from one season to the next is that _____.
water has a high specific heat capacity