3. A solid rubber ball is thrown so that it has an initial horizontal velocity of 12 m/s on a flat horizontal concrete surface, but is not initially rotating. Eventually friction will induce the ball to roll without slipping. Assuming you can neglect rolling friction, a) determine the amount of time after the ball is thrown that it begins to roll without slipping. b) determine the final center-of mass velocity without slipping.(adsbygoogle = window.adsbygoogle || []).push({});

2. Initially the ball sliding, so -Kinetic friction=ma this equals -mg(uk)=ma. According to my teacher "note that it doesn't initially start rolling without slipping, so you don't have the acceleration constraint. You do have,however, a constraint between their linear and angular speeds when it starts rolling without slipping." I took this as Vx=-w(omega) assuming the ball is thrown to the right, it will be rotating clockwise so angular velocity will be negative. When the ball is rolling w/o slipping Vcm=Iw(omega)R

I=2/5Mr^2

mu k=.0.80

I am really struggling and getting frustrated with this question, but this is what I have done so far. Obviously this can't depend on the radius or mass of this ball so every thing I'm trying to to cancel them out.

Initially the ball is undergoing translational motion only so I used N's 2nd law -kinetic frict=ma, so mg(uk)=ma. mass cancels a= -7.84 m/s^2

Now I'm lost and don't know what to do next, but here is my idea (Vx)f or -w= (Vx)i-a(delta t), I have two unknowns so guess I'm wrong. I need some major help!

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Rolling motion question

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