# physics

posted by .

i have to build a catapult that will fire a projectile that will pass a 1m tall wall 1 m away from starting point and land in a target 1 m away from the wall. the catapult cant be more than 23cm high.

I'm having some problems here with this

for simpicity issues
i said launch at .2m off the ground at origin and reach a height of 1.1m at 1m away just incase something screws up.

I need to find the
Vi
Vyi
Vxi

and am having some trouble and don't know what angle is best so that less speed is needed for this to work

• physics -

You have selected 0.2 m for the initial height and 1.1 m for the maximum height. That allows you to calculate the time the projectile must spend coming down (t2) and going up (t1).
(g/2) t2^2 = 1.1 m
t2 = 0.474 s
(g/2) t1^2 = 0.9 m
t1 = 0.429 s
Initial y component of velocity:
Vyi = g*t1 = 4.204 m/s

Total time of flight = 0.903 s
Vxi*0.903 s = 2.0 m
Vxi = 2.214 m/s

Vi = sqrt(Vxi^2 + Vyi^2) = 4.751 m/s

These two components determine the initial launch angle as
arctan(Vyi/Vxi) = 62.2 degrees

## Similar Questions

1. ### Physics

A catapult throws a projectile at a 40.0° angle with a velocity of 26.0 m/s. How high will the projectile reach, and how far away will the projectile land?
2. ### Physics

You are an artillery offcer attached to Gaius Julius Caesar's Xth Legion in the Gallic War (1st C. BCE). You are responsible for a catapult, a device with a long spoonlike arm used to lob stones or pumpkins over the walls of Gallic …
3. ### Physics

You are an artillery offcer attached to Gaius Julius Caesar's Xth Legion in the Gallic War (1st C. BCE). You are responsible for a catapult, a device with a long spoonlike arm used to lob stones or pumpkins over the walls of Gallic …
4. ### Physics

You are an artillery offcer attached to Gaius Julius Caesar's Xth Legion in the Gallic War (1st C. BCE). You are responsible for a catapult, a device with a long spoonlike arm used to lob stones or pumpkins over the walls of Gallic …
5. ### Physics

You are an artillery offcer attached to Gaius Julius Caesar's Xth Legion in the Gallic War (1st C. BCE). You are responsible for a catapult, a device with a long spoonlike arm used to lob stones or pumpkins over the walls of Gallic …
6. ### Physics I

I'm not sure how to address any of these. I"ve attempted them but each time I do, I've gotten different answers. I'm not even sure where to begin. 1. The Duke’s efforts to conquer the Count are starting to really falter. He has been …
7. ### physics

A knight sits on a castle wall during a siege.To while away the time, he notes that boulders catapulted from below land on the top of his wall with a vertical velocity of 9.9 m/s. If he is 35 m above the catapult, what is the initial …
8. ### Physics

A knight sits on a castle wall during a siege. To while away the time, he notes that boul- ders catapulted from below land on the top of his wall with a vertical velocity of 8.3 m/s. If he is 41 m above the catapult, what is the initial …
9. ### Physics

A knight sits on a castle wall during a siege.To while away the time, he notes that boulders catapulted from below land on the top of his wall with a vertical velocity of 5.7 m/s. If he is 45 m above the catapult, what is the initial …
10. ### Physics

A knight sits on a castle wall during a siege. To while away the time, he notes that boulders catapulted from below land on the top of his wall with a vertical velocity of 7.5 m/s. If he is 34 m above the catapult, what is the initial …

More Similar Questions