# A bullet question

1. Oct 20, 2005

### dragon513

I've just read the forum rule and fount out this is not the right place to ask school related question +_+ I'd really appreciate if any of moderators can move this question to the right h/w forum. Thank you.

This is solved.

Thank you

Regards,

Last edited: Oct 20, 2005
2. Oct 20, 2005

### Pengwuino

well for one... the answer is not correct. If it has an initial velocity of 630... why exactly would it slow down so much? It should stay at 630m/s for the entire trip (neglecting air resistance).

oops, and homework questions MUST be put in the homework section. Please read the titles.

3. Oct 20, 2005

### dragon513

Ya I think the question is a little misleading.
I think 630 m/s is when the bullet leaves the barrel.

4. Oct 20, 2005

### Staff: Mentor

The problem statement is a bit confusing. When it says "shot with an initial velocity of 630 m/s", what they really meant to say is that the bullet has the velocity of 630 m/s after leaving the barrel. (That's the initial speed of the rest of its trajectory.)

But during its acceleration in the barrel (which is what this problem has to do with), the initial velocity is zero (that's $v_0$, which is given as zero) and the final velocity (within the barrel) is 630 m/s.