Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: g



Hello
I have a problem with my calc-based physics students. The problem is=
over the sign of g, the gravitational acceleration.

I have told them the convention is that it is always downward even if=
the object is going upward. =20

I can't seem to explain to them why this is. They tell me the book s=
ays it is positive. That is not what the book says, the book says ex=
actly what I am saying.

How can I make it clearer to them about g and its sign?

Thanks
Tina

Tina Fanetti
Physics Instructor
Western Iowa Technical Community College
4647 Stone Ave
Sioux City IA 51102
712-274-8733 ext 1429

Howdy,

I always stressed that the sign of the COMPONENT of the acceleration
vector depended upon the particular coordinate system you set up and
that 'g' was the MAGNITUDE of the acceleration due to gravity. I've
always taken points away from students that don't define the
coordinate system they are using in a given problem; until that
coordinate system is defined the sign has no meaning.

Good Luck,
--
Herb Schulz
(herbs@interaccess.com)