In this unit, students will investigate torque and rotational statics, kinematics, and dynamics, in
addition to angular momentum and its conservation, to gain an in-depth and comprehensive
understanding of rotation. Students are provided with opportunities to make connections
between the content and models explored in the first four units, as well as with opportunities
to demonstrate the analogy between translational and rotational kinematics. Unfortunately,
when dealing with rotational motion, all the conceptual difficulties found in translational
motion also have direct analogs. For example, if the angular velocity is zero, students often
believe that the angular acceleration must also be zero. Astronomical phenomena (such as
satellites in orbit) are explored in Unit 7 to build students’ knowledge of angular momentum
and its conservation.
While earlier units focused on linear motion, Unit 6 pays close attention to the type of motion we
experience when we talk or listen to music. Through the concept of oscillations, students are
introduced to the model of simple harmonic motion (SHM), springs, and pendulums. Students
will discover why some objects repeat their motions with a regular pattern. They will also apply
the model of SHM, define the three kinematic characteristics (displacement, velocity, and
acceleration), and practice representing them graphically and mathematically. During their study
of oscillations, students will gain a more in-depth understanding of motion, making them better
equipped to apply their knowledge of forces and motion to waves. Students will continue to
expand on circular motion in Unit 7 as they explore celestial bodies and objects.
Unit 7 investigates Newton’s laws of gravity and the relationships shared between planets,
satellites, and their orbits. Students will become familiar with the law of universal gravitation
and how it can be applied to any pair of masses and will consider the motion of an object
in orbit under the influence of gravitational forces. Additionally, students will be given
opportunities to relate connected knowledge across units by applying and deriving Kepler’s
laws of planetary motion to circular or general orbits. Drawing such relationships will help
elevate students’ understanding of motion and force in various circumstances.