This essay focuses on the conservation of linear momentum. the conservation of linear momentum fter the collision. See the lab procedures
In this experiment, we will be measuring the velocities, momentum, and kinetic energy of a pair of gliders before and after the collide, and compare with the predictions based on the conservation of linear momentum. Part 1 of the lab is a simulation, and Part 2 is based on video analysis of actual lab runs.
1. Pre-lab Activities
Read the Physics 1A lab manual for this lab: Conservation of Momentum.pdf Note that we only examined the case of complete inelastic collisions (where the two objects get stuck together after the collision). The virtual lab will include both the elastic and inelastic cases. For the theory of one-dimensional
elastic collision between two objects, study the textbook and the video lecture. Also see Part 2 below.
For Part 1 of the lab (simulation), go to http://www.gigaphysics.com/momentum_lab.html (Links to an external site.) and read the linked document entitled, Elastic vs Inelastic Collisions. Also, familiarize yourself with the data collection in the virtual lab setup.
For Part 2 of the lab (video analysis),
Air-track Glider Collisions. Here you can run a series of video-recorded collisions, in a variety of scenarios with different masses and initial velocities. The collisions are mostly elastic, as the gliders do not touch each other during the collision, but rather repel each other via a magnetic force. When you consider both conservation carts as a system, this is an internal force, so it does not change the total linear momentum of the system.
These theoretical predictions can be tested in the video labs. To find the conservation velocities experientially, we use the distance. Over time method, conservation focusing on one glider at a time. Either before or after the collision. See the lab procedures below.
2. The Lab
/momentum_lab.html. (Links to an external site.) Follow the procedures listed in the document you read, Elastic vs Inelastic Collisions, and collect data to fill out all the entries for Parts I through IV — inelastic and elastic collisions. You don’t’ need to do Part V. (To do a new run with the same carts, click Start Carts.)
In Pivot Interactives, go to the lab
small mass at different speed A, at the bottom of the video screen. We need to find the velocities of each glider, both before and after the collision, from the video. To do so, focus on one glider at a time (say, the left one, before the collision). Deploy a timer, and note the initial portion of the glider — you may use a reference point, such as the right edge of the glider, and record its initial position (reading of the built-in yellow scale). Now run the video, and pause it after a short time interval Δ????Δt (under 1 second) — you must do so before the gliders get too close, when the magnetic force would have slowed them down significantly). See the screenshot below.