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## Homework Statement

A catapult launches a rock with an initial velocity of 50m/s at 35 degrees above the horizontal. The rock must clear 3.5m at 10m away in order to make it over a castle wall to get to the enemy. Do the knights succeed? By how much do they clear the wall or miss clearing the wall? (Ans: 3.1m)

## Homework Equations

__X-direction__[/B]

- Vfx=Vix: Vicosθ
- a= 0m/s
- Δx=Vix(t)

__Y-direction__- Viy=Visinθ
- Vfy-Visinθ+gt
- Δy=(visinθ)(t)+1/2gt^2
- Vfy^2=(Visinθ)^2+2gΔy
- Δy=1/2(Vfy+Visinθ)(t)
- a=-9.8m/s^2

## The Attempt at a Solution

I drew a picture. TheViy is 28.6. The Vix and Vfx is 40.9. The acceleration in the x-direction is zero. In the y-direction its -9.8m/s^2. Am I supposed to the Δy and then subtract it from 3.5 which is the height of the castle at 10m away?