posted by Anonymous .
A simple pendulum, 2.0 m in length, is released from rest when the support string is at an angle of 25 from the vertical. What is the speed of the suspended mass at the bottom of the swing?
Let A be the pendulum angle, which vaires sinusoidally with time. R is the pendulam length
R sin A = X
Xm = 2.0 sin 25 = 0.845 m is the oscillation amplitude (measured horizontally)
X = Xm sin (w t)
is the equation of motion
w is the angular frequency
w = sqrt(g/R) = 2.21 rad/s
Vmax = w*Xm = 2.21 rad/s*0.845 m
= 1.87 m/s