A blue ball is thrown upward with an initial speed of $v_{b0}$, from a height of $y_{b0}$ meters above the ground. $t_r$ seconds after the blue ball is thrown, a red ...
Blue balls, also known as epididymal hypertension, are a relatively harmless condition caused by the build-up of semen in the epididymis after prolonged sexual arousal without ejaculation.