(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A bullet of mass .0179kg (m) and speed v passes completely through a pendulum bob of mass 1.3kg (M). The bullet emerges with a speed of v/2. The pendulum bob is suspended by a stiff rod of length 1.08m (L) and negligible mass. What is the minimum value of v such that the pundulum bob will barely swing through a complete vertical circle?

Suppose that the pendulum bob is suspended from a light flexible cord instead of a stiff rod. Now what is the minimum value such that the pendulum bob will swing through a complete vertical circle? Answer in m/s

2. Relevant equations

1/2 mv^2 = mgh

m1v1 + m2v2 = m'v' + m''v''

3. The attempt at a solution

I already solved the first question and got it right. I used Energy conservation and momentum conservation equations to solve and got and answer of 945.0944 m/s.

The equation that I simplified down to to get my answer for question one was 4M/m(sqrt gl)

I am having a big struggle with the second part. I don't know what effect the flexible string will have on the equation. I know that when it reaches the top of the circle, it will have slack and want to fall back down, so the velocity has to be faster, but I don't know how to solve for it.

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# Homework Help: Pendulum Momentum Problem

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