- #1
yesiammanu
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Homework Statement
The wheel shown in the sketch below, is comprised of two 50.0 cm long thin rods of negligible mass and a thin metal ring with a mass of 10.00 kg, mounted on a very low friction bearing. A 100 gram lead weight is shot horizontally at the stationary wheel with an initial speed of 50.0 m/s and sticks to the rim of the wheel. What is the rotational speed of the wheel plus lead mass immediately after the collision? Give your answer in revolutions/second.
Homework Equations
I = mr^2
L = Iω
KE = 1/2 mv^2
KErot = 1/2 Iω^2
The Attempt at a Solution
1/2 mv^2 = 1/2 Iω^2
1/2(.1 kg) (50 m/s)^2 = 1/2( 10.1 kg )(.25 m)^2 ω^2
ω^2 = (125 kg * m^2 / s^2)/ .315625 kg * ms^2)
ω = 19.9 / s
Rotations = ω/2pi = 19.9/2pi = 3.16 rev/s
The answer is .315 RPS so I'm not sure what I'm doing wrong