A pendulum is made of a uniform slender rod (3.5 kg, 0.5 m long) pivoted at its top end O, with a solid sphere of mass 6.5 kg and radius 0.25 m fixed to its lower end. The centre of the sphere is 0.75 m below O. Find the mass moment of inertia IO of the pendulum about O.
Rigid-body rotation worksheet with answers
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A uniform slender rod of mass 2 kg and length 0.5 m hangs at rest from a frictionless pivot at its top end. A 30 g bullet moving horizontally at 160 m/s hits the rod 0.4 m below the pivot and stays embedded. Find the angular velocity ω of the rod just after the impact.
Answer key
- 1. IO = 4.11 kg·m²
- 2. t = 15.12 s
- 3. R = 40.47 N
- 4. α = 4.905 rad/s²
- 5. v = 7.696 m/s
- 6. ω = 11.2 rad/s
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