# Projectile motion

1. Sep 16, 2009

### ENCJ

1. The problem statement, all variables and given/known data
A projectile is fired at some angle theta to the horizontal with some initial speed vi, and air resistance is neglected. Which statements about the projectile are true? (Select all that apply.)

1.The projectile is a freely falling body.
2.Vertical acceleration is 9.8 m/s2, downward.
3.Vertical acceleration is 9.8 m/s2, upward.
4.Vertical acceleration depends on theta.
5.Horizontal acceleration is zero.
6.Horizontal acceleration depends on vi.
7.Horizontal acceleration depends on theta

2. Relevant equations
Vxi=vi*cos(theta)

3. The attempt at a solution
1.The projectile is a freely falling body.
2.Vertical acceleration is 9.8 m/s2, downward.
6.Horizontal acceleration depends on vi.
7.Horizontal acceleration depends on theta

2. Sep 16, 2009

### willem2

why do you think this is true?

3. Sep 16, 2009

### Anden

Most is correct, however I think you should more on what kind of acceleration affects horizontal movement if air resistance is neglected. There are 4 correct alternatives though.