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xTheLuckySe7en

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Thread moved from the technical forums, so no HH Template is shown.

__A wet umbrella is held upright and is twirled about the handle at a uniform rate of 21 revolution in 44 s. If the rim of the umbrella is a circle 1 m in diameter, and the height of the rim above the floor is 1.5 m, find how far the drops of water spun off the rim travel horizontally relative to the umbrella handle before they hit the floor?__

**The problem:**__My general set of goals for this particular problem were to first find the tangential velocity using the given values for revolutions per second, and then proceed with the tangential velocity as if it were a two-dimensional projectile problem.__

**My attempt:**ω = Δθ/Δt, where 1 revolution is equal to 2π (I got 3.0 rad/s)

Vt=rω, where r=.5m

Vt=1.5m/s

Then, I proceeded as aforementioned (two-dimensional projectile problem)

I started with Δy=-1.5m and solved for t using Δy=Vi*t+.5at^2, with a=-9.8m/s^2 and Vi=0m/s (should be no initial vertical velocity, as far as I'm aware).

I ended up getting t^2=.31s^2, and then t=.56s

Then, I used that t-value and solved for Δx in the equation Δx=Vi*t+.5at^2, with Vi equal to the tangential velocity and a=0m/s^2.

I ended up getting .84m (with intermediate roundings of values).

Ultimately, my professor marked me off four points out of ten total points and gave the real answer as .97m. I've been looking at it for a while now and cannot seem to find my obvious error. Help?