Question

A wheel of diameter 2 is with axle at o. A force of 2N is applied at B in the direction. calculate the moment of force about the center o
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Answer 1

Answer

• Moment of force = 2 N

Given

• A wheel of diameter 2 m is with axle at O. A force of 2 N is applied at B in the direction as shown in attachment

To Find

• Moment of force about the center O

Formula

$\bullet \;\;\; \rm \tau =rF.sin \theta$

where ,

• r denotes perpendicular distance b/w two points
• F denotes Force
• θ denotes angle b/w F & r

Solution

Diameter of wheel , D = 2 m

Force , F = 2 N

Perpendicular distance b/w F & r = Radius of wheel , r

⇒ r = D/2 = 2/2 = 1 m

Angle b/w Force acting and perpendicular distance is 90° [ ∵ both are ⊥ to each other ]

⇒ θ = 90°

So , Moment of force about the center O is ,

$\rm \tau = rF.sin \theta\\\\\implies \rm \tau=1 \times 2 \times sin 90\\\\\implies \rm \tau =2\ Nm$

More Info

• SI unit τ is N-m
• SI unit Force is Newton
• SI unit if Distance , r is meter