Dear Students,

I do pray that you are having a wonderful Thanksgiving holiday.  I want to remind you that although you have no official homework, your test on Work and Simple Machines will be Tuesday 30 November 2010.  I know that you all will do well as long as you study.  We have gone over everything on the test several times.  Make sure you know how to complete word problems, that is work on placing the correct value with the appropriate variable so that you can use the formulas properly.  Post any questions you have


11/29/2010 6:01pm

Hi Miss James i just wanted to ask what how do you calculate gravitational force.

11/29/2010 6:47pm

Ms.J on the power point how is a woman carrying a 20kg grocery to her car not work

11/29/2010 7:15pm

@ Christian,

In order for work to be done a force has to be applied. The definition of forces states that there must be a push or a pull on an object. No work is done on the grocery bag because it is being held, there is no push nor pull on the grocery bag.

In this situation the only work being done is on the muscles in the woman's body. Unfortunately we were considering the work done on an object external from the human body.

@ Jordan
F= ma
So take the mass in kg and multiply it by the acceleration due to gravity here on earth (9.81 m/s^2)

Jazsmine Peterson
11/29/2010 8:35pm

Ms.James how do you know if you are supposed to use IMA or AMA when you are calculating Mechanical Advantage?

C James
11/30/2010 12:49am

@ Jazsmine

the formulas are with the problems


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