Transcript AdvLessons#3

9/11/06
Lesson #8
Topic: Lab #1 Rotation
Objectives: (After this class I will be able to)
1.
2.
Become familiar with new lab procedures
Experiment to solve for I and compare to
calculated value for I
Lab Task: Verify that I=½mr2 for a uniform cylinder rotating about a
central axis
Assignment: “Mechanics of Rotation”
Lesson #9
Topic: Exam 1 Review
9/13/06
Objectives: (After this class I will be able to)
1. Practice all types of rotation problems
2. Review all concepts of rotation
3. Solve any rotational physics problem
Warm Up: The net work done in accelerating a propeller
from rest to an angular speed of 220 rad/s is 3000 J.
What is the rotational inertia of the propeller?
Assignment: “Rotational Exam Review”
Torque practice
1.
A ladder of length 2.0m and mass 1.0kg is leaning
against the wall such that the ladder makes an angle
of pi/3 with respect to the floor. With what horizontal
force must I exert on the bottom of the ladder to
prevent it from slipping and falling?
Assume no friction between the ladder and the wall
or floor.
2.
A 1.05kg ball on the end of a string is rotated in a
horizontal circle of radius 0.9m. Calculate the
rotational inertia, and torque needed to maintain a
constant angular velocity if air resistance exerts a
force of .08N onto the ball.
Torque practice
3. In order to get a flat uniform cylindrical
satellite spinning at the correct rate,
engineers fire four tangential rockets. If the
satellite has a mass of 2600kg and a radius
of 3m, what is the required steady force of
each rocket if the satellite is to reach 30rpm
in 5 min?