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Physics Question. Meter Stick and rotational motion.?
A meter stick is held to a wall by a nail passing through the 60-cm mark. The meter stick is free to swing about this nail, without friction. If the meter stick is released from an initial horizontal position, what angular velocity will it attain when it swings through the vertical position?
1 Answer
- NCSLv 76 years ago
Easiest as an energy problem.
Relative to the vertical position, the initial potential energy is
PE = mgh = M * 9.8m/s² * 0.10m = M * 0.98m²/s²
This gets converted into KE:
KE = M * 0.98m²/s² = ½Iω²
By the parallel axis theorem,
I = ML²/12 + Md² = M((1m)²/12 + (0.10m)²) = M * 0.093m², so
M * 0.98m²/s² = ½ * M * 0.093m² * ω² → M cancels
ω² = 21 /s²
ω = 4.6 rad/s
Hope this helps!