# Homework Help: Vector/Projectile Questions

1. Sep 20, 2009

### dabryanman

1. The problem statement, all variables and given/known data
A pitcher throws a baseball horizontally from the mound to home plate. the ball falls .809 m by the time it reaches home plate 18.3 m away. how fast was the pitchers pitch?

2. Relevant equations
c^2=a^2+b^2

3. The attempt at a solution
i drew a picture with .809 as the height (x) and 18.3 as the distance (y) and then used the pythagorean theorem to calculate they hypotenuse which was 18.3 and what i assumed to be the answer.

1. The problem statement, all variables and given/known data
A shell is fired from the ground with an initial speed of 1.74 multiplied by 103 m/s at an initial angle of 45° to the horizontal. Neglecting air resistance, find the shell's horizontal range. Find the amount of time the shell is in motion.

2. Relevant equations
Vx= vi(cos theta), x=(vi cos theta)(T)--->rearrange to get x/vi(cos theta)=t

3. The attempt at a solution
i solved for vx=1740(cos 45)=1230.4 but that was wrong. then i took 1230.4/1740(cos 45) and got 1 s for T which was wrong as well.

thanks for the help