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Oscillations

Solutions for the equation of motion


With the small-angle approximation the differential equation for the motion of the pendulum turns into

d2α/dt2 = - (g/) α


1. Note that this equation is independent of the mass m.
2. Note that this equation does depend on the acelleration g for gravitation.

Solutions are very similar to those for the mass-spring system.

α(t) = αmax sin(ωt)      for      ω = √ (g/)


and with the requirement that αmax should be small.

In the following videos Walter Lewin shows that the period of oscillation T=2π/ω does not depend on αmax as long as it is not too large and, furthermore, that the period of oscillation does not depend on the mass.



maximum angle