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

The string in a yo-yo is wound around an axle of radius 0.512 cm. The yo-yo has both rotational and translational motion, like a rolling object, and has mass 0.206 kg and outer radius 1.88 cm. Starting from rest, it rotates and falls a distance of 1.20 m (the length of the string). Assume for simplicity that the yo-yo is a uniform circular disk and that the string is thin compared to the radius of the axle. What is the speed of the yo-yo when it reaches the distance of 1.20 m? How long does it take to fall?

2. Relevant equations

mgh=1/2mv^2+1/2Iw^2

I=1/2mr^2

w=v/r

3. The attempt at a solution

r1=.512

r2=1.88

mgh=1/2mv^2+1/2(1/2mr2^2)(v/r2)^2

The answer is obviously incorrect. What exactly am I doing wrong? Thanks!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Yoyo problem

**Physics Forums | Science Articles, Homework Help, Discussion**