11/29

It's terrific Tuesday!!

Objective:  SWBAT design a lab that determines the factors that affect the period of a pendulum.

Warm Up:  Define Period (as used in physics).  Determine an appropriate way to measure the period of a pendulum.

11/28

Welcome back from break!

Objective:  SWBAT understand SHM.

Warm Up:  Turn in your Ch 10 outline.  Draw a simple sine wave.  Label:
crest, trough, amplitude and 1 wavelength.

11/21

Objective:  SWBAT prepare for tomorrow's test on rotational motion.

Warm Up:  Pick up your graded papers.
Pick up 3 pages for review and staple.
Answer question #1

11/18

Objective:  SWBAT calculate conservation of rotational momentum problems

Warm Up:  Turn in your chap 9 HW
Get out yesterday's WS.
Two children sit on a 1.5 m long teeter totter that has the pivot point offset, so that it is under the teeter totter 0.8 m from the left side.  The teeter totter's board weighs 20 N.  If the mass of the child on the left edge of the board is 50 kg,  how much does the child on the right side's mass need to be if they are sitting on the edge on the right side of the teeter totter?

11/17

Objective:  SWBAT calculate the moment of inertia of a rotating object.

Warm Up:  Watch the video clip below

This segment from a news program details the training regiment for Dana Carellas, a 15-year old figure skater. In a number of scenes, she performs a spin; as she comes out of the spin, she extends her arms out to the side to slow down. This is a typical problem utilizing the conservation of angular momentum in which the object’s moment of inertia changes so the angular velocity changes as well.

First, consider how her moment of inertia changes. Initially, Dana can be best represented by a spinning cylinder. Assuming her mass to be 50 kg and her “radius” to be 0.2 m, her moment of inertia is:

11/16

Objective:  SWBAT calculate the net torque on a system and determine where to place torques so that a system is in equilibrium.

Warm Up:  Fill in the chart on the board with the correct translational and rotational symbols for the kinematic and dynamic variables.

11/15

Objective:  SWBAT calculate problems invovling rotational kinematics.

Warm Up:  Pick up your graded papers.
3.8 rad = ? rev
22 rpm = ? rad/s
50 degrees = ? rad