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Informal sessions:

o Tu 3:30-4:20pm, RAS 218;

o Fri 4-4:50pm, ECJ 1.204.

Lecture 28 (iq24) Dynamics of a rigid-body-III

Trans. Q’s	Rot. Q’s	Cir. motion	Rigid-body
K=1/2 mv^2		K=1/2 mr^2w^2	K=1/2 Iw^2
Mom.	Rot. Mom. Ang-mom:L
p=mv	L=r^p	L= rmv =mr^2w	L = Iw
Force	Rot. force Torque: t
F = ma	t=r^F= r^ma	t = mr^2a	t = Ia
F=dp/dt	t=d(r^p)/dt	t = dL/dt	t = dL/dt

Demos:

§ Torque=lever arm * force

§ Conservation of angular mom.

§ Gyroscope

Rotational quantities as vectors: Cross product

Precession of a bike-wheel gyroscope

Reminders:

• Friday’s 4-5pm informal session: Questions in hw10 will be discussed.
• In anticipation of midterm 3 (Nov 12), it is a good time for you to review chapters: 10-13, hw8-10.
• Also preview chapter 14, and download hw11 when available.