How does a ballistic pendulum work?
ballistic pendulum, device for measuring the velocity of a projectile, such as a bullet. A large wooden block suspended by two cords serves as the pendulum bob. When a bullet is fired into the bob, its momentum is transferred to the bob. The bullet’s momentum can be determined from the amplitude of the pendulum swing.
What is the ballistic pendulum formula?
½ (m+M)vf2 = (m+M)gh. Apply conservation of momentum to determine the relationship between vf and the bullet’s speed before the collision.
Why is it called a ballistic pendulum?
The “ballistic pendulum” carries this name because it provides a simple method of determining the speed of a bullet shot from a gun. To determine the speed of the bullet, a relatively large block of wood is suspended as a pendulum.
What does a ballistic pendulum experiment demonstrate?
We use measurements obtained from a ballistic pendulum to review energy conservation, momentum conservation, and projectile motion. From the measured recoil speed of the pendulum we determine the speed of a ball fired by a spring-loaded cannon.
What happens to the kinetic energy in a ballistic pendulum?
By measuring the height of the pendulum’s swing, the potential energy of the pendulum when it stops can be measured. In the case of a pendulum total mechanical energy is conserved. So kinetic energy of the pendulum (after firing) is fully converted to potential energy.
When was the ballistic pendulum invented?
The ballistic pendulum was invented in 1742 by English mathematician Benjamin Robins (1707–1751), and published in his book New Principles of Gunnery, which revolutionized the science of ballistics, as it provided the first way to accurately measure the velocity of a bullet.
What is conserved in a ballistic pendulum?
While not all of the energy from the bullet is transformed into kinetic energy for the pendulum (some is used as heat and deformation energy) , the momentum of the system is conserved. By measuring the height of the pendulum’s swing, the potential energy of the pendulum when it stops can be measured.
How does friction affect ballistic pendulum?
Ballistic Pendulum Investigation Back to Physics Page. Energy is conserved, but many factors come into play when calculating energy after a collision. The farther the pellet from an air soft gun has to travel; air friction will act on it longer, therefore displacing the energy.
Does a ballistic pendulum conserve energy?
The ballistic pendulum is a classic example of a dissipative collision in which conservation of momentum can be used for analysis, but conservation of energy during the collision cannot be invoked because the energy goes into inaccessible forms such as internal energy.
What are components of ballistic pendulum?
Description of the ballistic pendulum: The device consists of a spring gun, a small steel projectile (a ball), a free-swinging pendulum catcher, and a ratchet ramp. The spring gun fires the projectile into the catcher which then swings up the ramp where it is caught by the notches.
Why momentum is conserved in ballistic pendulum?
The stationary pendulum now moves with a new velocity just after the collision. While not all of the energy from the bullet is transformed into kinetic energy for the pendulum (some is used as heat and deformation energy) , the momentum of the system is conserved.