Chapters 10 and 11 Energy, Power, and Work Do not copy anything that is underlined

10.1 __________ and __________ The __________ to produce change in itself or the __________ is called __________ __________ is also the __________ to do __________ __________ is the __________ of __________ __________ __________ is the __________ of motion __________ __________ is the __________ due to __________ of atoms (either gravitationally, chemically, or elastically)

__________ and __________ (1) When __________ is done, __________ is __________ from one object to another. Often this __________ is in the form of kinetic __________ __________ is done on an object only if the __________ acting on the object is not perpendicular to the motion of the object. The maximum amount of __________ is done when the __________ on the object and the motion of the object are in the same direction (i.e., parallel).

__________ and __________ (2) If an object is moving in the opposite direction of the force, then the __________ is __________ because it is removing energy from the object (such as the __________ of friction) NO __________ IS DONE ON AN OBJECT IF THE __________ AND __________ ARE PERPENDICULAR TO ONE ANOTHER!

Potential __________ The symbol for potential __________ is U Potential __________ is __________ that is __________ –Gravitational Potential __________ is __________ of __________ of an object. This __________ depends on how high the object is off of the ground and the __________ of the object –Elastic Potential __________ is the __________ stored in objects that can bend, such as __________. This energy depends on how far something is __________ and the “ __________ constant,” k, which determines how hard something is to __________

__________, More about __________ __________ is the __________ at which __________ is done The symbol for __________ is P The units of __________ are __________ (1 W = 1 J/s) The __________ is the amount of __________ __________. This might not always say that the __________ was a certain number, you may have to determine the amount of __________ __________ to determine the __________, and thus also the __________

Equations of Energy K = ½mv 2 Kinetic Energy U g = mghGravitational Potential Energy U s = ½kx 2 Elastic Potential Energy W = Fd cos  Mechanical Work P = W/tPower Turn to page __________

Example Problem on Page __________ W = Fdcos  W =  will always be zero unless stated W = Change in energy = __________ since work is a transfer of energy

Example Problem on Page __________ W = Fdcos  W =

Try Some on Your Own Practice Problems 1, 2, 4, 5, 6, 7 and 8 on pages 227 and 229

__________ With a Changing __________ If the __________ is changing, the way you would find the __________ done is through a graph The area under the __________ curve on a __________ graph is the __________

Determining Work from a Graph

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Power Example Problem on Page 230

Other Equations for __________ You can use any of the following equations for __________ : The first is the “definition” of __________, as __________ is the rate of __________ __________ Complete Practice Problems 9 through 12 on page __________

Chapter 11- __________ __________ has the ability to __________ forms, but it cannot be __________ or __________ __________ can be done on an object to __________ __________ to it This __________ can be in the form of __________ __________ or __________ __________ Turn to page __________

Example Problem Page 250

Try Some on Your Own Practice Problems Page __________ : 1b, 1c, 2 (skip a), 3, and 4 (Number 4 is a proportionality!)

Potential __________ (1) Potential __________ is stored __________ To find Gravitational Potential __________ (U g ), you find the amount of work done against gravity to lift it above the “reference level” A __________ level is an arbitrary point where we decide that U g is zero

Potential __________ (2) The __________ level is the lowest point (height) the object is in the problem The equation for U g is U g = ________ Turn to page __________ and read the example problem

Example Problem page _______ a.U g = b.U g = For the first problem, the __________ level is the floor, so you would use the __________ above the floor For the second problem, the __________ level is your head, so you would use the __________ above your head. In each part, the __________ found is what __________ it would have if it fell to the __________ level.

Try some on your own For homework do the following: 38, 39, 43, 44, 45, 46, 47, 50, 53, and 54 on pages for __________ Also do Practice Problems 5-8 on pages for __________

Elastic Potential __________ __________ stored in bonds that are stretched is elastic potential __________ Symbol: U s (S is for __________ ) Units: __________ Equation U s = ½kx 2 __ is something known as a __________ constant, or how easily something is stretched; and x is the distance it is stretched

Sample Problem Determine the elastic potential __________ of a __________ if it is stretched 22 cm with a __________ constant of 34 N/m.

11.2 __________ of Energy The law of __________ of energy states that __________ cannot be __________ or __________, it can only be converted In an equation, this would look like: This is for mechanical __________ only Mechanical __________ is gravitational, elastic, and kinetic energies

Example Problem Page 261

Try some on your own: Complete Practice Problems 9-11 on pages __________ ; skip 9a Complete Problems 58, 59, 61, 64, 65, 67, and 68 on pages __________

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