A ballistic pendulum is a simple device used to measure the velocity of a projectile, such as a bullet or a ball. The device consists of a pendulum, usually a heavy weight suspended from a fixed point by a string or rod, and a target, such as a wooden block or a metal plate, that the projectile can strike.
When the projectile strikes the target, the target moves with the bullet and the pendulum swings to a certain height, which is proportional to the kinetic energy of the bullet. By measuring the height of the pendulum swing and the mass of the pendulum, it is possible to calculate the velocity of the bullet using the principle of conservation of energy.
Here is a simple formula to calculate the velocity of the bullet using a ballistic pendulum:
v = √((2 * m * g * Δh) / (m + M))
v = velocity of the bullet (in meters per second)
m = mass of the bullet (in kilograms)
M = mass of the pendulum (in kilograms)
g = acceleration due to gravity (approximately 9.8 m/s^2)
Δh = change in height of the pendulum (in meters)
The ballistic pendulum is a relatively simple and inexpensive way to measure the velocity of projectiles and can be used for a variety of educational and scientific purposes. However, it is limited by the requirement that the pendulum and the target must be large enough to stop the projectile, and by the fact that it can only be used to measure the velocity of the projectile in a single direction. Nevertheless, it remains a useful educational tool and a valuable demonstration of the principle of conservation of energy. learn more about Digital Content.