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

11/16

If you missed Friday's test, you must make it up today or Tuesday A lunch!

Objective:  SWBAT understand angular velocity, acceleration, and rotational kinematics.

Warm Up:  Turn in your outline.
Why is it more fun to ride on the outer horse on a merry-go-round?

11/9

Objective:  SWBAT review for tomorrow's test.


Warm Up:  Turn in your Ch 7  HW now.  Can centripetal force do work on an object?

11/8

Objective:  SWBAT begin reviewing for Thursday's test.

Warm Up:  Find your review sheet for Work, Power, and Energy.
A 70 kg diver dives from a board that is 3 m above the water.  He leaves the board going upward at 6 m/s.  (Assume he essentially goes straight up, then comes straight down, missing the board).  What is the divers momentum when he leaves the board?  How high above the board will the diver go?  At what speed will the diver hit the water (assuming no air resistance)?

11/7

Objective:  SWBAT design a landing pad that will safely bring an egg that falls from the ceiling to the floor of the classroom to rest without cracking.

Warm Up:  Get into your teams.  Pre-read your lab.  THEN pick up the materials from Mrs. Heyes.

11/4

Wednesday was Test Day.  Thursday we took notes on Impulse- Momentum Theroem and Conservation of Energy.  This next unit is short but sweet, so stay on top of your studies!

Objective:  SWBAT understand how momentum factors into car accidents and explore ways that car manufacturers have used the Impulse-Momentum Theroem to reduce injuries from car crashes.

Warm Up:  Rhonda (whose mass is 55 kg) is driving 55 mph in her sports car when she crashes into a tree.  She is not wearing her seat belt and therefore the steering wheel stops her in 0.01s.  Compare the force on Rhonda from this crash to a crash in which her seat belt and an air bag stop her in 0.4 s.

11/1

Objective:  SWBAT review for tomorrow's test on work, power and energy.

Warm Up:  Turn in your HW.  Get out yesterday's review sheets.
A 0.5 kg football is thrown at an angle of 50 o with an intial velocity of 8 m/s from a height of 1.5 m.  What is the PEg of the ball at the top of it's trajectory?  What is KE at the top of it's trajectory?  If the ball is caught at the same height that it was thrown, how much work did gravity do on the ball?