Q about teaching gravity

[cc]

Hello

 

I came across a secondary school physics teacher recently who said that he explicitely teaches his pupils that gravity is not a force. His reason for this is that gravity is the field and weight is the name given to the force of gravity. This is giving me quite a headache for the following reasons:

 

Pros of teacher's argument:

1) He's right, as in nothing he said was factually incorrect.

2) Looking at the big picture, its kind of good that the teacher had a deeper knowledge of the subject than most science teachers.

 

Cons of teacher's argument:

1) He's just trying to be a smart-rse. I have a physics degree and no-one from my school teachers right up to university lecturers (who listed gravity as a fundamental force) has seen the need to pick apart the language of gravity in such a way. Thus I feel gravity being called a force is accepted by everyone else Ive ever met so why would the teacher be so picky?

 

So the questions Id like answered is does the teacher have a point and more importantly, should he be teaching kids this point? Is it an important distinction like weight/mass or substance/material, or is it just about the English language?

[insane_alien]

well, gravity is both a feild and a force. there is a gravitaional feild(much like an electrostatic feild) and objects within that feild experience a gravitaional force(much like an electrostatic force).

 

i wouldn't say he is wrong but it may cause confusion when the kids get another teacher. and really, gravitational force is just a fancy way of saying 'weight'

[swansont]

The use of "weight" is typically limited to near the surface of a celestial body. One would not, for example, usually refer to the gravitational attraction between the earth and the sun as the "weight."

 

IOW, W=mg and [math]F_g = \frac{GM_1M_2}{r^2}[/math]

 

So I disagree with that terminology — the former is weight, the latter is not.

[tvp45]

Most high school students are still rather concrete thinkers and will probably have an easier time understanding gravity as a force. They have experience with the idea of force (you can even do action at a distance with magnets and most of them won't raise eyebrows) and can apply that concept to gravity.

 

Most will not yet have conceptualized "fields". That is probably better left for university. All too often, high school teachers "show off" their knowledge and lose students who, at this time in their development, would be happy with simpler explanations.