group+005

=Pre-Lab=

Our experiment will include a collision of two pool balls. We will set up an incline on the edge of the pool table; a small distance from the incline, there will be another pool ball. The experiment overall includes us letting a ball roll down the incline and then collide with a second ball, which will be set at a designated spot on the table. To collect data, we will need a scale and a protractor, as well as measuring tape. We will mass the balls and record the numbers. Then we will measure the angle of the incline, the distance in the X and Y directions, and the distance that the second ball is set from the incline. We will then set up an X an Y chart and let the ball roll down the incline. We will record the forces due to gravity, etc. and then use our f net equations to figure out the acceleration. Once we find out the acceleration, we will use our knowns to solve for V f , which will be the V i for the collision. Then we will set up MVP charts to solve for the momentum and prove that momentum was conserved.

=Safety Precautions=

Making sure nobody gets hit with the ball, and that nobody trips on the ball.

=Equipment=

Pool table, pool balls, a material for the incline, paper tape (to mark the spots), measuring tape, scale, protractor.

=Procedure=

Our experiment consists of a pool ball rolling down a ramp hitting another ball and to find if the momentum is conserved in the collision. The first ball should transfer its momentum into the second ball making that move.

We used a combination of drawings, data tables, and charts to collect the data for this experiment. First, we set up an incline problem to solve for the Vf of the first ball. We used a PUKEM setup and proceeded to fill in our unknowns (Vf), our knowns (mass, Vi, A, and delta-x), the equation that we would use (vf^2=Vi^2+2a delta-x), and the missing (time) [We knew the acceleration because we solved for it using our fnet equations and the law of sines]. For the second part of the experiment (where we found time to solve for Vi of the second ball), we collected data by drawing a diagram of the situation and setting up charts- a separate one for each ball. On the charts, we recorded the trial number, as well as the time that we found. On the bottom of the charts is an average of the three times. Our group then set up our knowns and the equation that we would use to solve for the unknown (Vi). Once we knew the Vi, we were able to set up MVP charts to collect data for the third part of our experiment. We set up and labeled the mvp charts with ball one on the top and ball two on the bottom, and used all that we knew and found to fill them in and solve for momentum to try to prove that momentum was conserved.

In order to find our initial velocities we needed displacement, acceleration, and time. For our experiment we assumed the surface was frictionless, so the acceleration was 0. We picked a displacement to be .5m for the first ball and 1.0m for the second ball. We set up the experiment and timed how long it took for the first ball to roll .5m starting from directly after the collision, and we did the same thing with the second ball traveling 1.0m. We did three trials of this and used a ViVfdat equation to solve for Vi after the collision. To find the Vf of the first ball after it came off the ramp, we measured the angle of the ramp and found the parallel component of it for the acceleration. We also measured the lenght of the ramp for the displacement and the Vi was 0 because it started from rest. Then, we just plugged in the numbers to a ViVfdat equation to solve for Vf, which then converted into the Vi of the ball before the collision. =Data=



=The Video=

media type="youtube" key="UamTPFfI5r0" height="372" width="458"

=Conclusion=

Our momentum was not conserved entirely. When the balls hit each other they went pretty straight, but not perfectly straight. By only measuring the straight component, we were a little off in measuring total velocity because we didnt take the small perpindicular component into account. The ball that initiated the contact also came off at a slight angle that wasn't accounted for either. The initial velocities were also affected because we didn't solve for friction. This means that when the the ball came off the ramp it was moving faster than when it collided with the other ball. Also, when we solved for time we set up a track a meter long so as to get more accurate time data, however to do this we had to roll the balls on the wood floors which had slightly less friction.