Flag Mechanics> rotational-mechanics...
question mark

A straight rod of length L is released on a friction less horizontal floor in a vertical position .
As it falls( also slips) , the distance of a point on the rod from the lower end, which follows a quarter circular locus.
A) L/2 B) L/4 C) L/8 D) None.

krishna koushik pakala , 12 Years ago
Grade
anser 3 Answers
mohit yadav

Last Activity: 12 Years ago

none as no point on the rod makes circular path.only the lower piont will shift L/2 distancefrom its initial position.

lj

Last Activity: 7 Years ago

The disc tangents of point should be L/4 . It can be derived easily using instantaneous axis of rotation. They , if you still can not, ask in a different thread. Hope it helps.

Aviral Omar

Last Activity: 7 Years ago

Draw the FBD at any general point of time wherein mg acts at the centre of the rod and Normal acts at the point where it touches the floor.Balancing forces, we get N=mg.The reason the rod slips is due to unbalanced torques. A point which moves with a circular locus will be one about which the rod can be assumed to be rotating. Such a point is the Instantaneous Axis of Rotation.Assume this point is at distance r from bottom of rod. Balancing torque about this point,mg(l/2-r)sin θ=Nrsin θ. Put N=mg and r comes out to be l/4.

Provide a better Answer & Earn Cool Goodies

star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free