physics 50: lecture 11.1 richard craig. homework #10 chapter 10 we will skip 10.7 chapter 11...
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Homework #10 Chapter 10
We will skip 10.7 Chapter 11
Sections 1,2,3 only Exercises and Problems 10.1, 10.16, 10.41, 11.12, 11.14, 11.56 Due Tuesday April 14
Plan for the Day Some thoughts on Quiz of Tuesday Center of Mass and Center of Gravity Equilibrium Static Problems (things don’t move)
Simple: Board on benches Medium: Hammer Hard: Hanging sign
No Quiz (yeah!) but have short exit test
Center of Mass Formal Definition:
If density constant center of mass is just the geometric center of a body
If gravity constant center of gravity and center of mass the same point
For torque calculations a body acts as if all the weight is at the center of gravity (linear function unlike moment on inertia)
A rock is attached to the left end of a uniform meter stick that has the same mass as the rock. How far from the left end of the stick should the triangular object be placed so that the combination of meter stick and rock is in balance?
A. less than 0.25 m B. 0.25 m
C. between 0.25 m and 0.50 m D. 0.50 m
E. more than 0.50 m
Q11.2
Idea problem
A. T = w sin B. T = w cos
C. T = w/(sin ) D. T = w/(cos )
E. none of the above
Q11.3
A metal advertising sign (weight w) is suspended from the end of a massless rod of length L. The rod is supported at one end by a hinge at point P and at the other end by a cable at an angle from the horizontal.
What is the tension in the cable?
Tell me the answer to leave today………