A Slippery Slope

A Slippery Slope

CRA Description : 
In this activity, students will use a plane to study motion with constant acceleration as blocks of various materials slide down the plane at various angles of incline. The assignment assesses studentsʼ ability to understand concepts such as potential energy, kinetic energy, and the conversion of mechanical energy to other forms (via friction). Students will then relate those to kinematics results and to formulate predictions for how much mechanical energy is lost for specific block materials based on these understandings.
Subjects: 
Science
Physics
Key Concepts and Terms: 
Angle of inclination
Conservation of mechanical energy
Friction
Gravitational interaction
Inclined plane
Kinetic energy
Mechanical energy
Motion
Potential energy
Prior Knowledge: 
Students should understand concepts related to motion with constant acceleration (kinematics), mechanical energy, friction, thermal energy and the conservation of energy. They should have experience measuring and calculating distances, lengths, times, and masses as well as have a basic knowledge of mathematics and skills consistent with high school algebra, geometry, and trigonometry. Students do not need to understand concepts related to work and frictional forces, coefficients of friction, normal forces, etc., for success in this assignment. Students can simply consider energy loss per meter of track and how that changes for various angles of incline.

Comments

SInce I teach on-level Conceptual Physics, this lesson would require too much modification to make it worth the time to use.  Conceptual Physics minimizes the math and keeps the math at an Algebra 1 level.  The trigonometry required is way beyond the ability of my students.  Another problem with this CRA for me is that it introduces thermal energy too early while not using topics such as work and frictional forces.  I could see teaching this CRA to a Pre-AP Physics class of students taking Pre-Calculus concurrently.  Geometry teachers please teach your students some right angle trig because it is needed early in Physics and the Pre-Calculus teachers may not get to it soon enough.

Submitted by linchm (not verified) on