Particles 1 and 2, each of mass m, are attached to the ends of a rigid massless rod of length L1 + L2, with L1 = 19 cm and L2 = 75 cm. The rod is held horizontally on the fulcrum and then released. What is the magnitude of the initial acceleration of particle 1? What is the magnitude of the initial acceleration of particle 2?
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I = mL^2, L=L1+L2
I am not given mass and the answer needs to be numerical.
Tnet=I * alpha
How do I find the initial acceleration?
The rod is massless, so ignore it in I calculations. You know the I of each particle (1/2 m distance^2).
Now net torque= torque on log rod - torque on short end.
Torque around fulcrum= Itotal*angularacc
so solve for angular acceleration, then intial acceleration2= angularacceleration*distance2