Now, letâs get down to business â the cost! They do offer a 30 day free trial and then after that it is $7.95 a month or $79 a year. After just a few weeks of Nathan playing, I personally feel that the $7.95 a month is totally worth it!
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position.
A fixed counterweight is simply a heavy weight on the end of the short arm. Fixed counterweight designs tend to try an pull the treb over. Wheels are often used on trebuchet designs that use fixed counterweights to counter the tipping motion. The counterweight should be 75 to 100 times the weight of the projectile.