Finishing Chapter 11

Macroscopic: whole object Microscopic: atomic structure Microscopic energy is significantly larger therefore having great potential energy…atomic bomb.

Energy (heat) is the direct measurement of the atoms in an object Energy (heat) is the direct measurement of the atoms in an object. Therefore if an objects temperature rises, one can assume the molecular motion (microscopic motion) has increased.

Friction and drag are both non-conservative or dissipative forces Friction and drag are both non-conservative or dissipative forces. How does sliding a book across a table result in energy transformation?

Because dissipative forces ALWAYS increase thermal energy, both of the objects in a system will increase on thermal energy.

ΔK=Wnet ΔK = Wconservative + Wdissipative +W external Or ΔK = -ΔU + - Etherm + W external

Law of Conservation of Energy Esys is constant in an isolated system (K↔U↔Etherm) Emech= K+U if the system is isolated and no friction or drag exists.

Example 11.11

Energy can also be added to a system by “heating” it up Energy can also be added to a system by “heating” it up!!! This is know as the First Law of Thermal Dynamics ΔEsys= Wext + Q where Q is heat introduced by an external source such as a stove

Power Power is “how fast energy is transferred.” Power is in watts

Homework: Page 331 # 22,24,25,28,29, 30,31,35