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This week, we will
consider the special case

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of circular motion.

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The case where we know that the
motion is exactly constrained

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to have a circular geometry.

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This will consist of two parts.

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First, we will consider the
kinematics of circular motion.

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How do we describe the
trajectory, velocity,

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and acceleration of a particle
undergoing circular motion?

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We will consider
both the simple case

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of uniform circular motion,
where the object moves

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with constant speed, and also
nonuniform circular motion,

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where the object is speeding
up and/or slowing down

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as a function of time.

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We will see that a
Cartesian coordinate

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system proves awkward for
describing circular motion.

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And instead, we will introduce
the so-called polar coordinate

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system in terms of
the radius vector

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from the origin and its
position angle, which

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provides a much more
elegant description

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for circular motion.

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We will then examine the
dynamics of circular motion

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using Newton's second law to
understand what sorts of forces

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are required in order to
cause circular motion in both

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the uniform and
nonuniform cases.

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This will be the first
of several examples

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we will see in this course
of constrained motion.

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In this case, the constraint
is that the object

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moves in a circular path.