1. Physics 218: Mechanics Instructor: Dr. Tatiana Erukhimova Lecture 10

2. 90 80706049

3. The advantage of a pulley What minimum force F is needed to lift the piano of mass M?

4. The Elevator Problem

5. WORK (Chapter 7)

6. 2 or 3 D motion Definition of work: Kinetic energy: Work-energy theorem:

7. A person carries a bag of groceries of mass M with a constant velocity at the same height from the ground. Find the work done by a person on a bag.

8. Problem 1 p. 122 A man pushes up on a 100 kg block with a force such that it drops from 2 meters to the ground at a constant velocity. a)How much work is done by gravity? b)What is the magnitude of the force he exerts?

9. Have a great day! Hw: All Ch6 problems and exercises