Question
For full poitns I want to see the work and a correct answer.
Thank you.
a07. The diagram shows a rope passing around a circular wheel of radius 0. 500 meters. at t = 0s, a torque is applied to the wheel which in initially at rest. This torque is applied with two horizontal tensions, 90. 0 Newtons (lower rope) and F Newtons (upper rope), where F is unknown. assume the rope does not slip relative to the wheel as the wheel rotates and that the two forces are constant in magnitude and direction after t = 0s. The moment of inertia of the wheel about its axis of rotation is / = lOOkg. m2. If the angular momentum of the wheel is L = -500kg. m. s"2 at r=10 seconds, find the value of the unknown force F.
Explanation / Answer
%u03C9 is omega
%u03B1 is alpha
L=I*%u03C9
using L(10)=-500
%u03C9=-500/100=-5 rad/s
and
%u03C9=%u03B1*t
%u03B1=-5/10=-0.5
also
R*(90-F)=I*%u03B1
or
F=190N