Go to: Course homepage, Lectures

Informal sessions:

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

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

Lecture 22: Systems of particles -- II

• Concept of center of mass:

o An effective one-body

o Stability of an object

• Determine CM of an object based on its geometry
• Relative motion of the two bodies: Examples

Reminders:

Instructor’s informal session today: 4-5pm, ECJ 1.204, HW8.

Please check your exam2 %-score and scaled-score. You have made two letter-grades for the exam.

1. The “letter grade” based on the percent-score-cutoffs,

which are: 40%, 55%, 75% and 90% for D, C, B and A respectively;

2. The “letter-grade prime” based on scaled-score-cutoffs

which are: 400, 450, 525, and 600 for D, C, B and A respectively.

If your two letter-grades are not the same, the better is the one you have made. (See the firstday handout for more details)

Please record your exam-scaled score. We will revert to the original %-score display by the end of this week.