Posted by pete on .
A simple pendulum has a length of 1.5 m and is pulled a distance y = 0.24 m to one side and then released. (Assume small angle.)
What is the speed of the pendulum when it passes through the lowest point on its trajectory?
Is this horizontal distance? If so, draw the triangle. 1.5 down, .24 left, and hypotenuse is sqrt (1.5^2+.24^2)
but the pendulum is not that long, it is 1.5, so at what height is the bob at?
similar triangles: h/1.5=(sqrt(1.5^2+.24^2) -1.5)/1.5
solve for h.
then mgh=1/2 m v^2 solve for v.