When 1.000 kg of ice melts,33.00 $\times$ 104 J/kg of heat are needed.What is the entropy change in the melting process?

A) 758.0 J/K B) 1,227 J/K C) 1,684 J/K D) 2,316 J/K A) 758.0 J/K B) 1,227 J/K C) 1,684 J/K D) 2,316 J/K

A very efficient engine has the following characteristics - combustion = 1900$^{\circ}$C, exhaust = 430$^{\circ}$C, 7.0 $\times$ 109 cal of fuel produces 1.4 $\times$ 107 J of work in one hour.What is the output in hp?

A) 5.2 hp B) 8.1 hp C) 7.3 hp D) 6.3 hp A) 5.2 hp B) 8.1 hp C) 7.3 hp D) 6.3 hp

Exam 15: Thermodynamics

An engineer wants to use a river (minimum temperature of 4 $^{\circ}$ C)to cool his electrical plant which heats water with a boiler operating at 220 $^{\circ}$ C.If he wishes to produce 185 kW of power using this plant,what is the minimum energy he must supply to his boiler if it is maximally efficient?

(Multiple Choice)

4.9/5

(66)

Question 41

A refrigerator uses 40.0 J of work to extract 90.0 J from a heat reservoir at 0.00 $^{\circ}$ C.What is the coefficient of performance for the refrigerator?

(Multiple Choice)

4.8/5

(83)

Question 42

A heat pump is used to heat a house in Minnesota in the winter and has half the ideal coefficient of performance for a reversible heat pump.If the outside air temperature is -15 $^{\circ}$ C and the indoor temperature desired is 20 $^{\circ}$ C,what is its coefficient of performance under these conditions?

(Multiple Choice)

4.7/5

(78)

Question 43

1.50 moles of an ideal gas freely expands from 1.00 liter to 4.50 liters.The change in entropy in the expansion is

(Multiple Choice)

4.9/5

(78)

Question 44

When 1.000 kg of ice melts,33.00 $\times$ 10⁴ J/kg of heat are needed.What is the entropy change in the melting process?

(Multiple Choice)

4.9/5

(73)

Question 45

An engineer uses a river (which averages 4 $^{\circ}$ C)to cool his electrical plant which heats water with a boiler operating at 750 $^{\circ}$ C .What's the maximal performance (in terms of efficiency)theoretically possible for this electrical plant?

(Multiple Choice)

4.8/5

(78)

Question 46

A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle.How much heat does it exhaust in each cycle?

(Multiple Choice)

4.8/5

(67)

Question 47

A heat pump uses 100 J of work to output 150 J of heat at some temperature.What is the coefficient of performance for the heat pump?

(Multiple Choice)

4.8/5

(85)

Question 48

120 J of heat flows by thermal conduction from 100 $^{\circ}$ C to 0.00 $^{\circ}$ C.What is the change in entropy for this process?

(Multiple Choice)

4.9/5

(82)

Question 49

A engine goes through a cyclic process.During the cyclic process the engine does 600 J of work and has a heat output of 2400 J.What is the efficiency of the engine?

(Multiple Choice)

4.8/5

(80)

Question 50

A system in a certain macro state has 1.2 $\times$ 10³ microstates.Through some process,the system changes the number of microstates to 3 $\times$ 10⁴.What is the change in entropy for the process?

(Multiple Choice)

4.9/5

(88)

Question 51

An ideal reversible heat pump is used to heat a house in Minnesota in the winter.If the outside air temperature is -15 $^{\circ}$ C and the indoor temperature desired is 20 $^{\circ}$ C,what is the expected coefficient of performance for the heat pump under these conditions?

(Multiple Choice)

4.7/5

(68)

Question 52

If 1.00 mol of oxygen is heated at constant pressure of 1.00 atm from 10.0 $^{\circ}$ C to 25.0 $^{\circ}$ C.What is the work done by the gas during this expansion?

(Multiple Choice)

4.9/5

(83)

Question 53

It can be shown that the change in entropy in heating or cooling a sample is given by the relation $\Delta$ S = mc ln (T_F/T_i),where m is the mass of the sample,c is the specific heat of the sample,and T_F and T_i are the final and initial temperatures respectively.What is the change in entropy when 20.0 grams of aluminum with a specific heat of 0.9 J/gm K is heated from 10.0 $^{\circ}$ C to 60.0 $^{\circ}$ C?

(Multiple Choice)

5.0/5

(78)

Question 54

10 joules of heat energy are transferred to a sample of ideal gas at constant pressure.As a result,the internal energy of the gas

(Multiple Choice)

4.8/5

(83)

Question 55

A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle.How much work does it perform in each cycle?

(Multiple Choice)

4.9/5

(87)

Question 56

A very efficient engine has the following characteristics - combustion = 1900 $^{\circ}$ C, exhaust = 430 $^{\circ}$ C, 7.0 $\times$ 10⁹ cal of fuel produces 1.4 $\times$ 10⁷ J of work in one hour.What is the output in hp?

(Multiple Choice)

4.7/5

(87)

Question 57

What is the maximum theoretical efficiency possible for an engine operating between 100 $^{\circ}$ C and 400 $^{\circ}$ C?

(Multiple Choice)

4.8/5

(88)

Question 58

An ideal,reversible refrigerator keeps food in the freezer portion at -15 $^{\circ}$ C and dumps excess heat into the kitchen,whose temperature is 20 $^{\circ}$ C.What is the refrigerator's coefficient of performance under these conditions?

(Multiple Choice)

5.0/5

(84)

Question 59

When an ideal gas adiabatically expands

(Multiple Choice)

4.8/5

(79)

Question 60

Showing 41 - 60 of 81

Exam 15: Thermodynamics

A refrigerator uses 40.0 J of work to extract 90.0 J from a heat reservoir at 0.00 ∘^{\circ}∘ C.What is the coefficient of performance for the refrigerator?

1.50 moles of an ideal gas freely expands from 1.00 liter to 4.50 liters.The change in entropy in the expansion is

When 1.000 kg of ice melts,33.00 ×\times× 104 J/kg of heat are needed.What is the entropy change in the melting process?

An engineer uses a river (which averages 4 ∘^{\circ}∘ C)to cool his electrical plant which heats water with a boiler operating at 750 ∘^{\circ}∘ C .What's the maximal performance (in terms of efficiency)theoretically possible for this electrical plant?

A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle.How much heat does it exhaust in each cycle?

A heat pump uses 100 J of work to output 150 J of heat at some temperature.What is the coefficient of performance for the heat pump?

120 J of heat flows by thermal conduction from 100 ∘^{\circ}∘ C to 0.00 ∘^{\circ}∘ C.What is the change in entropy for this process?

A engine goes through a cyclic process.During the cyclic process the engine does 600 J of work and has a heat output of 2400 J.What is the efficiency of the engine?

A system in a certain macro state has 1.2 ×\times× 103 microstates.Through some process,the system changes the number of microstates to 3 ×\times× 104.What is the change in entropy for the process?

An ideal reversible heat pump is used to heat a house in Minnesota in the winter.If the outside air temperature is -15 ∘^{\circ}∘ C and the indoor temperature desired is 20 ∘^{\circ}∘ C,what is the expected coefficient of performance for the heat pump under these conditions?

If 1.00 mol of oxygen is heated at constant pressure of 1.00 atm from 10.0 ∘^{\circ}∘ C to 25.0 ∘^{\circ}∘ C.What is the work done by the gas during this expansion?

10 joules of heat energy are transferred to a sample of ideal gas at constant pressure.As a result,the internal energy of the gas

A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle.How much work does it perform in each cycle?

A very efficient engine has the following characteristics - combustion = 1900 ∘^{\circ}∘ C, exhaust = 430 ∘^{\circ}∘ C, 7.0 ×\times× 109 cal of fuel produces 1.4 ×\times× 107 J of work in one hour.What is the output in hp?

What is the maximum theoretical efficiency possible for an engine operating between 100 ∘^{\circ}∘ C and 400 ∘^{\circ}∘ C?

An ideal,reversible refrigerator keeps food in the freezer portion at -15 ∘^{\circ}∘ C and dumps excess heat into the kitchen,whose temperature is 20 ∘^{\circ}∘ C.What is the refrigerator's coefficient of performance under these conditions?

When an ideal gas adiabatically expands

Introduction

Force

Acceleration and Newtons Second Law of Motion

Motion With Constant Acceleration

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

Sound

Temperature and the Ideal Gas

Heat

Electric Forces and Fields

Electric Potential

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Reflection and Refraction of Light

Optical Instruments

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Quantum Physics

Nuclear Physics

Particle Physics

Filters

A refrigerator uses 40.0 J of work to extract 90.0 J from a heat reservoir at 0.00 $^{\circ}$ C.What is the coefficient of performance for the refrigerator?

When 1.000 kg of ice melts,33.00 $\times$ 10⁴ J/kg of heat are needed.What is the entropy change in the melting process?

An engineer uses a river (which averages 4 $^{\circ}$ C)to cool his electrical plant which heats water with a boiler operating at 750 $^{\circ}$ C .What's the maximal performance (in terms of efficiency)theoretically possible for this electrical plant?

120 J of heat flows by thermal conduction from 100 $^{\circ}$ C to 0.00 $^{\circ}$ C.What is the change in entropy for this process?

A system in a certain macro state has 1.2 $\times$ 10³ microstates.Through some process,the system changes the number of microstates to 3 $\times$ 10⁴.What is the change in entropy for the process?

An ideal reversible heat pump is used to heat a house in Minnesota in the winter.If the outside air temperature is -15 $^{\circ}$ C and the indoor temperature desired is 20 $^{\circ}$ C,what is the expected coefficient of performance for the heat pump under these conditions?

If 1.00 mol of oxygen is heated at constant pressure of 1.00 atm from 10.0 $^{\circ}$ C to 25.0 $^{\circ}$ C.What is the work done by the gas during this expansion?

A very efficient engine has the following characteristics - combustion = 1900 $^{\circ}$ C, exhaust = 430 $^{\circ}$ C, 7.0 $\times$ 10⁹ cal of fuel produces 1.4 $\times$ 10⁷ J of work in one hour.What is the output in hp?

What is the maximum theoretical efficiency possible for an engine operating between 100 $^{\circ}$ C and 400 $^{\circ}$ C?

An ideal,reversible refrigerator keeps food in the freezer portion at -15 $^{\circ}$ C and dumps excess heat into the kitchen,whose temperature is 20 $^{\circ}$ C.What is the refrigerator's coefficient of performance under these conditions?