[quote author=Fu-Kwun Hwang link=topic=1116.msg4279#msg4279 date=1242351064]
You can click the stop button to pause the simulation and drag the black dot to change length and angle of the pendulum (the velocity will be set to zero when you drag the black dot).
You can drag the end of the velocity arrow to change it's velocity and watch how tension force changed,too!
Hi Prof, I don't think the black dot is drag-able.
BTW, this is a great vertical circular motion applet.