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.
The ballistic pendulum is a device to measure the momentum of a bullet. The pendulum bob is a block of wood into which the bullet is fired. The bullet is stopped within the block and its momentum transferred to the pendulum. This momentum is determined from the amplitude of the pendulum swing. See Ballistics