Question

Sample problem: 4
A uniform wheel of 600 mm diameter, weighing 5 kN rests against a rigid rectangular block of 150 mm
height as shown in Figure. Find the least pull, through the center of the wheel, required just to turn the
wheel over the corner A of the block. Also find the reaction on the block. Take all the surfaces to be
smooth.
​

Answer 1

Let P = least pull required just to turn the wheel Least pull must be applied normal to AO.

F.B.D of wheel is shown in fig.b

from the sin θ = 150/300

θ = 30º

AB = {3002 – 1502}1/2

= 260 mm

Now taking moment about point A considering body is in equilibrium

P X 300 –5 X 260

= 0 P = 4.33 KN

Calculation for reaction of the block

Let R = Reaction of the block

Since body is in equilibrium resolving all the force in horizontal direction and equate to zero

R cos 30º – P sin 30º = 0

R = 2.5KN.

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