A "ballistic pendulum" is a device (now largely obsolete, but very useful in its day) to measure the speed of a bullet as it hits a target. Let the target be a block of wood suspended from a string, as in the figure below. When the bullet hits, it is embedded in the wood, and together they swing, like a pendulum, to some maximum height h. The question is, how do you find the initial speed of the bullet (vi) if you know the mass of the bullet (m1), the mass of the block (m2), and the height h ? |

In a ballistic pendulum, a gun is fired into a block of wood ha... | Filo