Chapter 14 Flashcards
The kinetic energy of an object increases when its ___________ increases.
Speed
According to the kinetic theory of matter, as air gets hot, the air ________________ and ________________.
Expands, rises
List two materials that become hot easily
metal and rock
List two materials that do not become hot as easily as the materials listed before
wood and plastic
If a block of metal at 10 C is placed next to a block of metal at 40 C on a table that is in a room at room temperature, what is likely to happen?
The hot block will cool and the cool block will become hotter.
What does not require an input of energy?
condensation
If the same amount of energy is added to 5 g of water and to 50 g of water, which sample will have the higher temperature?
The 5 g of water.
Temperature is a measure of the average _______________ energy of an object’s particles.
Kinetic
What is the name of a temperature scale?
Celsius, Fahrenheit and Kelvin.
Convert 75 C to degrees Fahrenheit
75 x 1.8 + 32 = 167 F
The temperature at which all molecular motion stops is
0 K
Convert 500 F to degrees Celsius
500 - 32 / 1.8 = 260 C
When one feels a warm oven, the sensation of warmth is the result of
Energy transfer
Convert 300 K to the Celsius scale
300-273 = 27 C
Convert 458 K to the equivalent Fahrenheit temperature
(458-273) x 1.8 + 32 = 365 F
The energy transferred between objects with different temperatures is
Heat
What temperature is impossible to measure?
-20 K
The reason is because 0 K is absolute zero.
_______________ describes how much energy is required to raise an object’s temperature.
Specific heat
Calculate the energy transferred when raising the temperature of 16 kg of water by 3 C (c=4,186 K/kg . K)
(4186)(3)(16) = 2.0 x 10^5 J
_____________ does not involve the movement of matter.
Radiation
Calculate the specific heat for a 20 g piece of metal if 30 J of energy is required to raise its temperature by 12.5 K
30 / (0.02)(12.5) = 120 J/kg . K
A material that is a poor conductor of energy
Insulator
Characteristic physical property of a substance, denoted by the letter c
Specific heat
The transfer of energy as heat through a material
Conduction
Energy transferred as electromagnetic waves
Radiation
A material through which energy is easily conducted
Conductor
The movement of fluids due to density differences caused by temperature variations
Convection
Heat always moves from an object of _______________ temperature to an object of ______________ temperature.
Higher, lower
A drill bit will get hot after extended us. This is because of
Mechanical heating
Solar panels gather _____________ energy from the sun.
Radiated
When energy is transformed, the amount of usable energy
Decreases ?
A solar heating system that utilizes and electric fan to move warm air throughout a home is called a(n) ____________ system.
Active ?
What contains insulation material?
Plastic-foam cup
Evaporation causes a __________ effect.
Cooling
Heat engines use ____________ to convert potential chemical energy and internal kinetic energy into mechanical energy.
Combustion
An engine transforms chemical energy of a fuel into work done by
Pistons ?
The total amount of energy (both usable and unusable) in any process
Remains constant
What are the units of energy?
Joules (J)
