chapter 5 physical science
The pressure at the bottom of a barrel filled with liquid does not depend on the
area of the liquid surface.
The freezing point of a substance is always lower than its
boiling point
In an isolated system, entropy
cannot decrease
The entropy of a system is a measure of its
disorder
Suppose there were molecules that had no attraction whatsoever for one another. A collection of such molecules would form a
gas
Of these substances, the one with the lowest specific heat is
gold
When a liquid freezes to become a solid,
it gives off heat.
When a liquid becomes a vapor,
it must absorb heat.
Ice floats in water because
its density is less than that of water.
When heat is added to a body of matter, the resulting temperature increase does not depend upon
its shape
The heat a refrigerator absorbs from its contents is
less than it gives off.
If a cake of soap is placed in a bathtub, and sinks to the bottom, the buoyant force on the soap is
less than its weight.
The pressure on the bottom of an object inside a liquid is
more than the pressure on its top.
The "heat death" of the universe refers to a possible (although improbable) future in which all of its molecules are
moving with the same average speed
The physics of a heat engine cannot be used to understand the operation of a
nuclear reactor
Heat transfer by convection occurs
only in liquids and gases
Which of the following formulas expresses the relationship between the pressure and absolute temperature of a gas sample whose volume is fixed?
p1/t1=p2/t2
A refrigerator
removes heat from a region and carries it elsewhere.
Of the following, a molecule is best described as
the smallest particle of a substance that is representative of the substance.
Sublimation refers to
the vaporization of a solid without first becoming a liquid
An absolute temperature of 100 K is the same as a Celsius temperature of
-173°C.
The specific heat of ice is 2.1 kJ/kg°C. When 50 kJ of heat is removed from 2 kg of ice initially at -5°C, the final temperature of the ice is
-17°C.
At which of the following Celsius temperatures will a Fahrenheit thermometer show the same reading in degrees?
-40°C
A 400-kg concrete block is 1 m long, 0.6 m wide, and 0.3 m high. Its density is
2222 kg/m3.
Fifty kJ of heat is added to a 10-kg piece of lead at its melting point of 330°C and 2 kg of lead melts. The heat of fusion of lead is
25 kJ/kg.
Which of the following formulas relating temperatures on the Celsius and Fahrenheit scales is correct?
Tc = (5/9)(TF - 32°)
Heat transfer by conduction occurs
in liquids, solids, and gases.
Of the substances below, the one with the highest specific heat is
water
When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200°C to 85°C. The specific heat of copper is
0.39 kJ/kg°C.
The melting point of water is 0°C. Its freezing point is
0°C
A 400-kg concrete block is 1 m long, 0.6 m wide, and 0.3 m high. It can exert three different pressures on a horizontal surface, depending on which face it rests on. The highest pressure is
13.1 kPa.
The specific heat of water is 4.2 kJ/kg°C. The heat needed to warm 8 kg of water from 20°C to 70°C is
1680 kJ.
An ideal frictionless engine takes in 10 kJ of heat per second when it operates between 500 K and 400 K. The work that the engine does per second is
2 kJ
The density of brass is 8 × 103 kg/m3. The volume occupied by 320 g of brass is
38 cm3.
In order to double the average energy of the molecules in a gas at 200 K, its temperature must be changed to
400 k
If it is to be 40 percent efficient, a heat engine that exhausts heat at 350 K must absorb heat at a minimum temperature of
583 K.
The specific heat of water is 4.2 kJ/kg°C. How long will it take for a 2-kW heating element to raise the temperature of 30 kg of water from 20°C to 80°C?
63 min
The density of air is 1.3 kg/m3. The air in a room 5 m long, 4 m wide, and 2.5 m high has a mass of
65kg
A temperature of 20°C is the same as
68°F
Ethanol boils at 172°F. The Celsius equivalent of this temperature is
78°C