# I have a stupid professor and need clarification on newtons 2nd law

1. Oct 26, 2009

### pmangs06

So is it true that if you have a constant velocity therefore you have no change in acceleration so A=0 and if you have no acceleration then you have no Fnet? And is that the case in ANY force problem?
Thanks!

2. Oct 26, 2009

### Gear300

More or less. A net force results in an acceleration, and no net force is 0 acceleration, which includes constant velocity situations. Technically, you could exert a force that accelerates an object to a certain velocity and then stop exerting the force; you now have an object at constant velocity with no net force (or a net force of 0N) acting on it.

3. Oct 26, 2009

### pmangs06

AKA that's the whole idea of Newton's first law or the idea of inertia. Like if you toss a ball in the air, your hand no longer exerts a force on the ball but gravity acts on it therefore it has to come back down otherwise it would keep going.

4. Oct 26, 2009

### xxChrisxx

I fail to see how this makes your professor stupid.

5. Oct 26, 2009

### pmangs06

...because he didn't actually teach me any of this and I had to learn basic concepts, like this, all on my own because he can't keep on the same train of thought for more than 1 minute so he never fully develops the full idea we are supposed to be learning.

6. Oct 26, 2009

### arildno

Sounds more like he is succinct in his explanations. Follow EACH word he says very carefully..

7. Oct 26, 2009

### symbolipoint

Hard to know, since we do not attend your class. Does he state a definition, explain a concept, give maybe 2 examples? Review the examples in class? Is your textbook smart and sensible (like the kind as Sears, Zemansky, & Young)? How has the drop rate been in your class, and how does this compare to classes of the same course taught by other professors?