1. Oct 2, 2007

### jbutl3r25

A cannon ball is fired from a catapult at 13.5 m/s at 24 degrees above the horizontal.
a. How long is it in the air?
b. What is the horizontal component of the velocity?
c. How far from the catapult does the ball land?

I used a program on my calculator that we are allowed to use and got the X Magnitude to be 12.3 and the Y Mag. to be 5.5..with that i filled in this chart:

vX 12.3
dX
t

vfY 5.5
voY
dY
t
aY -9.8

i need a third component in the Y column, then i can figure out how to do the rest. How would I go about finding it?

2. Oct 2, 2007

### Kurdt

Staff Emeritus
You really shouldn't need to use a program on your calculator. I think it rather defeats the object of learning about projectiles. Have you been taught the kinematic equations? They can be found in this thread: https://www.physicsforums.com/showthread.php?t=110015

You should be able to work out everything given these and hopefully understand projectile motion better.

3. Oct 2, 2007

### jbutl3r25

yeah we weren't taught that..

but im thinking that what i may have done is but the 5.5 in the wrong spot? or should the original velocity be zero?

4. Oct 2, 2007

### Kurdt

Staff Emeritus
The original speed in the y direction will be 5.5 ms-1. The final speed will be the same but in the opposite direction.