Science/9/Physics 1.0 Newton's laws predict the motion of most objects. As a basis for understanding this concept:
a. Students know how to solve problems that involve constant speed and average speed.
b. Students know that when forces are balanced, no acceleration occurs; thus an object continues to move at a constant speed or stays at rest (Newton's first law).
c. Students know how to apply the law F=ma to solve one-dimensional motion problems that involve constant forces (Newton's second law).
d. Students know that when one object exerts a force on a second object, the second object always exerts a force of equal magnitude and in the opposite direction (Newton's third law).
e. Students know the relationship between the universal law of gravitation and the effect of gravity on an object at the surface of Earth.
f. Students know applying a force to an object perpendicular to the direction of its motion causes the object to change direction but not speed (e.g., Earth's gravitational force causes a satellite in a circular orbit to change direction but not speed).
g. Students know circular motion requires the application of a constant force directed toward the center of the circle.
h. * Students know Newton's laws are not exact but provide very good approximations unless an object is moving close to the speed of light or is small enough that quantum effects are important.
i. * Students know how to solve two-dimensional trajectory problems.
j. * Students know how to resolve two-dimensional vectors into their components and calculate the magnitude and direction of a vector from its components.
k. * Students know how to solve two-dimensional problems involving balanced forces (statics).
l. * Students know how to solve problems in circular motion by using the formula for centripetal acceleration in the following form: a=v2/r.
m. * Students know how to solve problems involving the forces between two electric charges at a distance (Coulomb's law) or the forces between two masses at a distance (universal gravitation). 2.0 The laws of conservation of energy and momentum provide a way to predict and describe the movement of objects. As a basis for understanding this concept:
a. Students know how to calculate kinetic energy by using the formula E=(1/2)mv2 .
b. Students know how to calculate changes in gravitational potential energy near Earth by using the formula (change in potential energy) =mgh (h is the change in the elevation).
c. Students know how to solve problems involving conservation of energy in simple systems, such as falling objects.
d. Students know how to calculate momentum as the product mv.
e. Students know momentum is a separately conserved quantity different from energy.
f. Students know an unbalanced force on an object produces a change in its momentum.
g. Students know how to solve problems involving elastic and inelastic collisions in one dimension by using the principles of conservation of momentum and energy.
h. * Students know how to solve problems involving conservation of energy in simple systems with various sources of potential energy, such as capacitors and springs.
After reviewing basic energy concepts, students will design a new snowboarding event through the use of the free physics simulation program “Skateboard Park.” Students will investigate the energy dynamics their course and explore the conservation of energy principle.
Students will learn about the energy dynamics of a skateboarding park. Students will learn the relationship between total energy, kinetic energy, and thermal (dissipated) energy. Students will also analyze and evaluate a design for safety.
Students will be able to:
Use simulation software to design an original skate park course.
Use simulation software to analyze the energy of a skater at various locations on a course.
Explain the principle of conservation of energy.
Use energy pie charts and bar graphs to analyze the energy dynamics in a simulated skate park.
Describe the changes in potential energy and kinetic energy as a skater moves through a course.
Explain the role of friction in a real world skate park or snowboarding competition.
Explain at least one safety consideration for snowboarding course designers.
Computers with internet access or downloaded java applet “Skate Park.” Ideally you will have 1 computer per 2 students.
Anticipatory Set (Lead-in):
Has anyone ever been to or seen a skateboard park or snowboarding run? What aspects of these places make them exciting for participants and observers? Believe it or not, although many skaters and snowboarders don’t particularly like all rules, they just can’t break the laws of physics. In this lesson we are going to look at a particular law, the law of conservation of energy, but first let’s watch a video on the physics of snowboarding.
Lesson Plan Procedure:
Note: This lesson assumes some familiarity with energy concepts such as kinetic energy, potential energy, and thermal (dissipated) energy. If students are not familiar with these terms then they should be clarified and discussed before watching the video.
Part 1 (10-15 minutes)
Explain that the class has been selected to design a new type of snowboarding course (for the 2014 Winter Olympics which will be held for the first time in Russia.) In order to complete this task they will use a physics simulation program to explore the energy dynamics of a skater in a skate park.
Either create your own half pipe using the simulation program, or show the attached “Discussion Slides” 1-6, and discuss with the class both how the program works and the energy dynamics of the skater in a simulated half pipe. (Note: the program is very user friendly and students generally learn how to use it very quickly on their own, or working in small groups.)
Depending upon the level of the class, you may also want to view the optional slides 7-11 that examine frictional effects and safety considerations.
Part II Simulation Activity (35-40 minutes)
Hand out the activity worksheet: Conservation of Energy in a Skate Park.
Have groups find another group and compare designs and answers before sharing final thoughts in an all-class discussion.
At the end of the period, you may want to have students rotate around to other stations and vote on the top design.
Closure (Reflect Anticipatory Set):
Ask students about the differences that must be taken into account when designing a simulated skate park and a real world skate park. Ask students about the differences between designing a real world skate park and a real world snowboarding course.
Assessments & notes
Plan for Independent Practice:
Students can access this free site from any internet connected computer or download the program on a disk or thumb drive. They can explore the features in more depth including the loop feature and write about their discoveries.