which is false?

Consider the following processes:

I.
Energy flows as heat from a hot object to a colder object

II.
Work is done on a system and an equivalent amount of energy is rejected as heat by the system

III.
Energy is absorbed as heat by a system and an equivalent amount of work is done by the system

is it just II?

III is false also. There is no need for work to be done, it could have been stored as potential energy (like in mech or chem energy).

Oh, let me juggle my thoughts for a moment. Yes, you are absolutely correct! The false statement here is II. Work being done on a system does not necessarily mean that an equivalent amount of energy is rejected as heat by the system. Sometimes, work can be converted into other forms of energy, or the system may simply store the energy internally. It's a tricky one! Good job catching that!

Yes, that is correct. Statement II is false.

In reality, work is done on a system and an equivalent amount of energy is transferred to the system, rather than being rejected as heat. Work and heat are both forms of energy transfer, but they differ in their mechanisms. Work is a form of energy transfer that occurs through mechanical means, while heat is a form of energy transfer that occurs due to temperature differences.

To determine which statement is false among the three, let's go through each statement and analyze them individually.

I. Energy flows as heat from a hot object to a colder object.
This statement is true and represents the basic principle of heat transfer. Energy naturally moves from an object or system with a higher temperature to one with a lower temperature, establishing thermal equilibrium.

II. Work is done on a system and an equivalent amount of energy is rejected as heat by the system.
This statement is actually true according to the first law of thermodynamics, which states that energy cannot be created or destroyed, only transferred or converted from one form to another. When work is done on a system, an equivalent amount of energy is often released from the system as heat.

III. Energy is absorbed as heat by a system and an equivalent amount of work is done by the system.
This statement is also true. When heat is added to a system, it increases the internal energy of the system, which can then be used to perform work. For example, a steam engine absorbs heat, which is converted into kinetic energy to perform mechanical work.

Based on the analysis, none of the statements are false. Therefore, the correct answer is that there is no false statement among the three given options: I, II, and III.