Physics 2065A/B Study Guide - Midterm Guide: Ground Speed, Sagitta, Viscoelasticity
Document Summary
Intro: kicking a ball is a skill and highly variable; in experiment kicker couldn"t tell if ball did or didn"t have helium in it. Results: avg helium ball went 3yds further; bc of variability btwn kicks, there is statistically no difference. Helium effect on ball: weight empty, full of air, full of helium- 410g, 3. 2 g at 13psi, -0. 9% less than empty ball. Reasoning: helium is only half as dense as air so sound travels through it twice as fast . Speed of sound in a gas: cs= square root of [( /p) times p] where is the constant, p is pressure and p is density; fhe ~ 3 fair ratio of densities. Football facts: regulation nfl football 13 psi, 90kpa; circumference middle btwn 52. 7 and 54, and around the ends 70. 5-72. 4 with the length 14-14. 2 (all in cm); weight is 397-425g; shape of prolate ellipsoid.
