cure & Re shows the arrangement for this experiment. From your study of projectile motion, you know the Do mater what the horizontal velocity of a ball coming off the ramp is, it will take the same time to fall to the ficoz This means that you can use the horizontal displacement of the ball from its position during the collisions a measure of its velocity. Since the time taken to fall for either ball will always be the same, let that time be one arbitrary time unit (tu). If, for example, the horizontal displacement of the struck ball was 32 cm, then its velocity 1 = 32 cm/tu. incident ball "tee" plumb bob displacement or velocity carbon paper newsprintfloat himhim theredcar ing the barironed dup acemend of the bat from its puution during the pool Procedure I Sat in the ipponyingure 3. it Placesare Shortend corben caper with the camen mis range foods dun theone hen thenwhymap . that in tcclike ain the target bull which should ies bicritical with the To Chapterl MommastimesArrange the target ball so that the collision will be oblique (Le, the incident ball will strike the target ball of the angle other than head-onl. Let the incident ball run down from the very top of the ramp and collide with the target ball. Mark the landing positions of both balls. Repeat four more times and average the displacement of pach ball after the collision. be sure to record the angles between the two balls after the collision. Also record the angle between their displacement vectors and the displacement vector the incident ball would have haut ithad not collided with the struck ball. You need to know the direction of the initial momentum vector. 7. Draw a vector diagram (scaled down if necessary) showing the following: (a) the momentum of the incident ball before the oblique collision (b) the momentum of the incident ball after the collision (c) the momentum of the struck ball after the collision the vector sum of the momenta of the incident ball after collision and the struck ball after the collision Label these vectors respectively: P. . P. . Ps , and Pa. Concluding Questions 1. Compare the total momentum before with the total momentum after a head-on collision of two steel balls of equal mass. Calculate the percent difference between the two, and discuss sources of error. 2 Compare the resultant momentum of the incident and struck balls after an oblique collision, with the momentum of the incident ball before the collision. if there is a difference, remember you must use the vector difference. 3. What percent is the magnitude of the vector difference between pa and p. of the initial momentum, P. of the incident ball? Discuss sources or error. Challenge 1. Repeat procedure steps 1 to 7, using a steel ball colliding with a less massive glass ball. Note that you can no longer use just displacement vectors to compare momenta. Each displacement (velocity) must be multiplied by the appropriate mass. 3.3 Review Questions 2. A 2.5 x 105 kg car travelling west at 6.0 m/s is hit by 1. A hockey player of mass 82 kg is travelling north a 6.0 x 105 kg truck going south at 4.0 m/s. The two with a velocity of 4.1 m/s. He collides with a 76 kg vehicles lock together on impact. What is the speed player travelling east at 3.4 m/s. If the two players and direction of the wreckage immediately after lock together momentarily, in what direction will impact? they be going immediately after the collision? How fast will they be moving? Chapter 3 Momentum and Energy 71 Edvantage Interactive 20207. Draw a vector diagram (scaled down if necessary) showing the following: (a) the momentum of the incident ball before the oblique collision (b) the momentum of the incident ball after the collision (c) the momentum of the struck ball after the collision (d) the vector sum of the momenta of the incident ball after collision and the struck ball after the collision Label these vectors respectively: p. . P . P, , and PA