Question

2. (40 points) A soccer ball tester consists of a 15-kg slender rod AB with a 1.1-kg sim- ulated foot located at A and a torsional spring located at pin B. The torsional spring has a spring constant of k 910 N.m/rad and is unstretched when AB is its lowest position. Fig. 2 depicts the simulation. The length of AB is 0.9 m, and you can assume that the foot ban be modcled as a particle, Knowing that the velocity of the 0.45- soccer ball is 30 m/s right after impact, and that the mass moment of i ncrtia of AB center of mass is IaAB mR where Roadius of gyration of the rod. Determine: Torsional spring Figure 2: Problem 2 (a) (10 points) Angular velocity of AB right before the impact. (b) (10 points) Angular and linear velocities of AB and the foot right after the impact. (c) (10 points) The cocfficient of restitution of the impact. (d) (10 points) All the impulses exerted during the impact.

Answer 1

Ven mAR: 15 Ka nm Position 1 Position 1 Arlying Enerj con serral gibOn potential Energy + K1he: tic Ener拧,Constant 15×0.92 KAm2 K2-m2 fool 0.95 P 2 Scanned with GamScanner CS

910 I7, 2 1198-5969 = 2.4705102 ひー22.02 Red | set Inaulasvelo 0 fust be fore inpacet lomlmCenseavan afet eRe, hel - 30 al らAu S Scanned with CamScanner

20.28 Rad/sec u>, :) Angu las velocity of AB and fook afteRzm贮1, linear Velou 308 95 Bau)3 pal 2 0.54 chanze n momen tum mpulse Exesteo Ball 0.45 х(20-0, kg-m 13-5 Cs Scanned with CamScanner