- #1
JLPG
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Homework Statement
A solid rod of mass M = 1.35 kg and length L = 83 cm is suspended by two strings, each with a length d = 71 cm (see Figure), one at each end of the rod. The string on side B is cut. What is the magnitude of the initial tangential acceleration of end B?
http://gauss.vaniercollege.qc.ca/webwork2_files/CAPA_Graphics/Gtype20/prob13a.gifThe string on side B is retied and now has only half the length of the string on side A. What now is the magnitude of the initial tangential acceleration of end B if it's cut again?
http://gauss.vaniercollege.qc.ca/webwork2_files/CAPA_Graphics/Gtype20/prob13b.gif
Homework Equations
a(tangential)= rα
α=Torque/I
I=1/3MR^2
The Attempt at a Solution
Given: m=1.35kg
L=.83m
d=.70m
I= (1/3)(1.35)(.83)^2=.31 kg*m^2
Torque= Frsinθ
F=ma
F=(1.35*9.8)=13.23N
Torque=13.23(0.83)=10.98N*m
α=10.98/.31= 35.42kg*m^2
a(tangential)= 0.83(35.42)=29.4 m/s^2
I haven't tried b) yet because a) isn't the right answer