Practice
Test 
Study
Guide 


Essential Question: What is energy? 
Linear and Rotational Kinetic Energy

State that kinetic energy cannot be negative.

Solve problems in which work = change in kinetic energy.

Demonstrate that while momentum is conserved, kinetic energy is not conserved in an inelastic collision.

State the mathematical definition of rotational kinetic energy.
K = 1/2 I w^{2}

State that the total kinetic energy of an object is the sum of rotational and linear kinetic energies, because energy is a scalar. Note: rotational and linear momentum cannot be added together.

Demonstrate that while momentum is conserved, kinetic energy is not conserved in a spinning ice skater problem.
Homefun (formative/summative assessment): Read sections 11.1, problems 1, 2 page 287 


Formative
Assessment: Physics Investigation 
Title 
Video Analysis of an Elastic Collision 
Research Question 
Determine if both momentum and kinetic energy are conserved in elastic collisions of 2 carts on a track. 
Background 
Physics has 2 simplified methods of modelling collisions that can be used to analyze real world conditions: elastic and inelastic models. Both contain the simplifying assumption that fricition forces are negligible. Momentum is conserved in both cases and kinetic energy is conserved for elastic models. 
Hypothesis 
If a video analysis of the collision indicates a negligible loss of kinetic energy and momentum in the collision then it can be reasonably modeled as elastic. 
Data,
Calculations 
Using Logger Pro software, perform video analysis on the elastic collision video with equal mass in the Advanced Physic Mechanics folder. Make a table and report velocities, kinetic energies, and momentums for the carts both before and after the collisions, calculate the % momentum and % kinetic energy lost during the collision. 
Conclusions 
Answer the research question, discuss sources of error and possible improvements. 
Follow up Questions 

Deliverables 
Lable your Logger Pro video analysis file "elastic momentum analysis <your name>" and save it in the honors physics folder in your virtual student hard drive. Turn in a handwritten copy of the above data table with your conclusion 
Resources/Materials 
Logger Pro software and video files. 
Formative
Assessment: Physics Investigation 
Title 
Video Analysis of an Inelastic Collision 
Research Question 
Determine if both momentum and kinetic energy are conserved in an inelastic collision of 2 carts on a track. 
Background 
Physics has 2 simplified methods of modelling collisions that can be used to analyze real world conditions: elastic and inelastic models. Both contain the simplifying assumption that fricition forces are negligible. Momentum is conserved in both cases and kinetic energy is conserved for elastic models. 
Hypothesis 
If a video analysis of the collision indicates a negligible loss of momentum in the collision then it can be reasonably modeled as obeying conservation of. 
Data,
Calculations 
Using Logger Pro software, perform video analysis on both the elastic collision videos in the Advanced PhysicsMechanics folder. Make a table and report velocities, kinetic energies, and momentums for the carts both before and after the collisions, calculate the % momentum and % kinetic energy lost during the collision. (Note: kinetic energy loss should be high in an inelastic collision.)
The left cart mass = 1.043 kg, the right cart mass = 0.514 kg 
Conclusions 
Answer the research question, discuss sources of error and possible improvements. 
Follow up Questions 

Deliverables 
Lable your Logger Pro video analysis file "elastic momentum analysis <your name>" and save it in the honors physics folder in your virtual student hard drive. Turn in a handwritten copy of the above data table with your conclusion 
Resources/Materials 
Logger Pro software and video files. 

Essential Question:
Can kinetic energy be considered stored energy? 
Potential or Stored EnergyGravitational Potential Energy
 Define potential energy in terms of work. Potential energy is work done against a conservative force
 Gravitational potential energywork done against gravity
 Spring (elastic) potential energywork done to compress or elongate a spring

Calculate gravitational potential energy (flat Earth model). U_{g} = mgh, Note that an arbitrary reference point must be selected as having zero gravitational potential energy. Depending on the reference selected, U can be negative.

State a condition that should be satisfied when modeling a system as though it has a constant level of mechanical energy.
No energy is lost as heat
 Write an energy balance equation for systems that can be modelled as having constant mechanical energy (conservation of mechanical energy).
ME = K + U
K_{before} + U_{before} = K_{after} + U_{after}
 Solve problem in which mechanical energy is considered to be constant.
pendulums
frictionless slopes
free fall (no air resistance)
Homefun (formative/summative assessment) problems 5, 6,7 p. 291.



Essential Question: How have springs affected history in critical ways? 
Spring or Elastic Potential Energy
Relevance: The practical understanding of spring potential energy has been a significant factor in shaping history with technologies such as bows and arrows, catapults, modern fire arms, clocks, vehicles, etc.
 Calculate potential energy for a spring.
U_{s} = 1/2 kx^{2}^{}
k= F/x , k is called a spring constant and is a measure of spring stiffness
 Solve constant mechanical energy problems with springs.
spring launcher
spring bowling
 Describe examples of simple harmonic motion in terms of energy
pendulum
spring and mass system
Homefun (formative/summative assessment):Section Review Problems 9, 10, 11; page 292 
Essential Question: Why have conservation of mass and conservation of energy merged into a single law? 
The 1st Law of ThermodynamicsConservation of Energy
Relevance:The 1st law of Thermodynamics is as close to absolute truth as anything in science.

State the 1st Law of Thermodynamicsconservation of energy.

Explain what is meant by rest energy.
E_{o} = mc^{2}^{}
 Solve problems in which some mechanical energy is lost as heat.
falling with air resistance
slopes with friction
bullets
Homefun (formative/summative assessment): problems 59, 61, 74 page 273

Essential Question:
How can you best prepare for the
test? 
Review
Formative Assessments:

Work review problems at the board

Work practice problems.
Metacognition Problem Solving Question:
Can I still work the problems done in class, several hours
or days later?
Some amount of repetition on the exact same problems is necessary to lock in
learning. It is often better to thoroughly understand a single example of a
problem type than to work example after example understanding none of them
completely.
Relevance: Good test preparation is
essential to performance in physics class.
Homefun (formative/summative assessment): turn in on the day stapled to the back of the test.
Summative Assessment: Unit exam objectives 117 

