Counter the horizontal, uniform rod shown .n the diagram. The left end 0/ the ro
ID: 1349029 • Letter: C
Question
Counter the horizontal, uniform rod shown .n the diagram. The left end 0/ the rod is supported by a hinge and the right end is supported by a cable. THe force exerted on the left end of the rod by the hinge Greeted... vertically upward, down and to the right, down and to the left, up and to the right. horizontally to the rightWhen a certain torque is applied to a turntable that is mitiaiy at rest, reaches an anQular speed of 33 3 rpm in a time or 2 seconds. If the torque applied to theturntable is doubled, how long will C take for the turntable to reach r angular speed cf 33 3 rpm (starting from rest)?Explanation / Answer
As we can see there will tension T in wire. that is making angle 30 deg with vertical and 60 deg with the rod.
In horizontal , there are two forces one is due to hinge Fx and other is component of tension.
Tension in horizontal = Tcos60 to left.
to balance this force as rod is in eqilirrium . horizontal force due to hinge have to towards rigt side .
Fx towards right side.
balancing moment about cable point, (L /2 ) x mg + (L x Fy) = 0
as we can see that to balance torque vertical force due to hinge have to be upwards .
so Net force due to hinge =Fx i + Fy j
so direction up and to the right.
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torque = I x alpha
alpha = torque / I
wf = wi + alpha *t
as it starts from rest so wi = 0
wf = alpha*t
t =wf / alpha
now torque is doubled.
so alpha will also get doubled.
so time get halved. t' = t/2 = 1 sec