## anonymous 5 years ago A 42 ball is fired horizontally with initial speed toward a 100 ball that is hanging motionless from a 1.1 -long string. The balls undergo a head-on, perfectly elastic collision, after which the 100 ball swings out to a maximum angle = 52.

1. anonymous

what is the question

2. anonymous

$KE_0+PE_0=KE_f+PE_f$ $h = l-(lcos(52))$ $(1/2)m_bv_0^2+0 = mgh \rightarrow mg(l-lcos(52))+(1/2)m_bv_f^2$ find vf or $KE_0+KE_{angular_0} = KE_f+KE_{angilar_{final}}$

3. anonymous

$KE_{angular} = (1/2)I\omega^2$ $I_{sphere} = (2/5)mr^2$