Variable-mass system events. The following derivation is for a body that is gaining mass (accretion). A body of time-varying mass "m" moves at a velocity v at an initial time "t". In the same instant, a particle of mass dm moves with velocity u. The initial momentum can be written as Now at a time "t" + d"t", let both the main body and the particle accrete into a body of velocity v + dv. Thus the new momentum of the system can be written as Since d"m"dv is the product of two small values, it can be ignored, meaning during d"t"
This Is What Rock n' Roll Looks Like week, the song went up two spots, peaking at number forty-four. The following two weeks, "This Is What Rock n' Roll Looks Like" remained stationary at number forty-four on the weeks ending August 1, 2011 and August 8, 2011, respectively. A music video for "This Is What Rock n' Roll Looks Like" was shot and directed by Sanaa Hamri at Citrus College in Glendora, California. Porcelain Black discussed the idea behind the music video for "This Is What Rock n' Roll Looks Like" with AOL's Carlos Ramirez, stating it was based on real life experiences. After Porcelain Black's mother had