A 6.0 kg bowling ball is stopped in the middle of the gutter. A second bowling ball of mass 4.5 kg is thrown down the gutter and strikes it with a velocity of 5.2 m/s. If the collision is elastic, what are the final velocities of the two balls?
208.8 comes from the expansion of the terms inside the squared bracket.
(23.4 - 6V2f)^2 simplifies to
(23.4 - 6V2f)*(23.4 - 6V2f)
23.4*23.4 - 23.4*6V2f - 23.4*6V2f + 6V2f*6V2f
547.56 - 140.4V2f - 140.4V2f +36V2f^2
547.56 - 280.8V2f +36V2f^2
The -280.8V2f term comes from the two middle terms of the expansion. If you remember FOIL (first, outside, inside, last); these are the outside and inside terms.
thanks for help. question, at 5:17, where does 208.8 come from?
imwithdumbhead 5 months ago
@imwithdumbhead
208.8 comes from the expansion of the terms inside the squared bracket.
(23.4 - 6V2f)^2 simplifies to
(23.4 - 6V2f)*(23.4 - 6V2f)
23.4*23.4 - 23.4*6V2f - 23.4*6V2f + 6V2f*6V2f
547.56 - 140.4V2f - 140.4V2f +36V2f^2
547.56 - 280.8V2f +36V2f^2
The -280.8V2f term comes from the two middle terms of the expansion. If you remember FOIL (first, outside, inside, last); these are the outside and inside terms.
fyfadmin 5 months ago