- #1

scratchfish

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## Homework Statement

http://s2.webstarts.com/exploring-my-thought/index.html

Find the kinetic energy of the system of bodies B1, B2 and B3 at an instant when the speed of B1 is 5ft/sec (the image is linked above)

radius of B2 = 2ft

mass of B1 = 32.2lb

mass of B2 = 32.2lb

mass of B3 = 96.6lb

answer is 25ft-lb

## Homework Equations

translational kinetic energy: K = 1/2mv

^{2}

rotational kinetic energy: K = 1/2Iw

^{2}

## The Attempt at a Solution

B1 = 1/2(32.2)(5)^2 = 402.5 ft-lb

B2 = 1/2((mr^2)/2)(5/2) = 201.25 ft-lb

B3 = 1/2(96.6)(5)^2 = 1207.5 ft-lb

My answers are way off, what am I doing wrong?

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