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--- demonstrations:1_mechanics:1m_work_and_energy:ballistic_pendulum:start [2019/02/14 23:33] – external edit 127.0.0.1
+++ demonstrations:1_mechanics:1m_work_and_energy:ballistic_pendulum:start [2020/01/29 17:44] (current) – demoroom
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 ====== Ballistic Pendulum ======
-{{tag> needs_review untagged unlocated}}
+{{tag> mechanics kinetic_energy ballistic measurement pendulum located}}
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 ===== Description =====
-Demonstrate an inelastic collision
+Consists of a spring-loaded mechanism that fires a brass ball, a pendulum, and a curved scale. The pendulum has a catching mechanism which catches the brass ball, and a ratchet on the bottom. When the pendulum catches the ball it starts the end of it starts travelling along the curved scale. The ratchet on the bottom of the pendulum only allows the pendulum to progress one way up the scale, causing it to come to a standstill as soon as it starts swinging back towards the starting position.
-Inelastic collision, conservation of energy.
 ===== Purpose =====
+  * To demonstrate the usage of a ballistic pendulum in measuring the velocity of a projectile
-. To show a ballistic pendulum as a method of measuring the velocity of a fast-moving object
+  * To demonstrate a nearly-perfectly-inelastic collision.
-. An example of an inelastic collision
 ===== Apparatus =====
-- Ballistic pendulum
+  * Ballistic pendulum
-- Air gun
-- Blackboard
 ===== Setup =====
+  - Start by removing the brass ball from the pendulum and placing it on the end of the firing mechanism.
-. Draw a scale on the blackboard which shows the angles the pendulum can swing to.
+  - Push the firing mechanism in by the brass ball until the trigger engages with the firing mechanism. At this point if you stop pushing on the brass ball, it shouldn't pop back out. (You may want to raise the pendulum out of the way during this step.)
-. Shoot the pendulum.
+  - Make sure the pendulum is at rest at the lowest part of it's swing.
-. Have the students' watch where the pendulum swings to (watch for parallax).
+  - Pull the trigger on the firing mechanism.
-. Do a simple calculation demonstrating the speed of the pellet when it hit the pendulum.
+  - Observe the height that the ballistic pendulum reached.
 ===== Notes =====
-Be extra careful with this demonstration as the air gun can cause damage to soft tissue.
+If you want to perform an actual measurement of the kinetic energy or velocity of the ball, this can be done too. The mass of the ball and the mass of the pendulum are noted on the base of the demo. The only detail you need in addition to that is the height of the scale relative to the resting height of the pendulum, since the scale starts from zero.
 Wikipedia Article on Ballistic Pendulum: [[ http://en.wikipedia.org/wiki/Ballistic_pendulum |  http://en.wikipedia.org/wiki/Ballistic_pendulum]]
-Updated on 01/21/16
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-| **Location** | ---- |
+| **Location** | LMN0 |
 | **Maker** | Unknown |
 | **Current State** | Working |