Thermodynamics II Law

The Law of Conservation of Energy states:

• Energy can created or destroyed but not transformed 
• Energy cannot be created or destroyed, it can only transformed
• Energy can't be created, destroyed or transformed

The _____ Law of Thermodynamics says that heat always flows from an object with a higher temperature to an object of lower temperature naturally

• Zeroth
• First
• Second
• Third

Tags

NGSS.HS-PS3-4

How does a refrigerator work?

• Moves heat from inside the fridge to the room
• Blows cold air into the fridge
• Uses convection cells
• It generates cold air

Tags

NGSS.HS-PS3-4

An ice cube is placed on a table and begins to melt.  The following conclusion can be made.

• Energy is being absorbed by the table which causes the cube to melt.
• Energy is being transferred from the table to the ice cube.
• Energy is being created by the air and table and making the cube heat up.
• Energy  is being created by the ice cube and is being released to the air

Tags

NGSS.HS-PS3-4

A gas is heated by supplying it with 250 kJ of

energy; at the same time, it is compressed

so that 500 kJ of work is done on the gas.

Calculate the change in the internal energy of

the gas.

• 250 kJ

• 750 kJ

• -250 kJ

• 500 kJ

Tags

NGSS.HS-PS3-1

A heat engine

• converts heat input to an equivalent amount of work

• converts work to an equivalent amount of heat

• takes heat in, does work, and loses energy heat

• uses positive work done on the system to transfer heat from a low temperature reservoir to a high temperature reservoir

• uses positive work done on the system to transfer heat from a high temperature reservoir to a low temperature reservoir

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

A Carnot cycle

• is bounded by two isotherms and two adiabats on a p-V graph

• consists of two isothermal and two constant volume processes

• is any four sided process on a p-V graph

• only exists for an ideal gas

• has an efficiency equal to the enclosed area on a p-V diagram

A Carnot engine operates between 200°C and 20°C. Its maximum possible efficiency is

• 90%

• 100%

• 38%

• 24%

• 72%

A hot cup of tea absorbs thermal energy from a cold room.

• True
• False

Tags

NGSS.HS-PS3-4

Cycle efficiency is defined as ...

• 1 - Q_c/Q_h
• the amount of work added 
• the amount of heat added - amount of heat removed
• the amount of heat added