Advertisements
Advertisements
Question
A half metre rod is pivoted at the centre with two weights of 20gf and 12gf suspended at a perpendicular distance of 6 cm and 10 cm from the pivot respectively as shown below.
1) Which of the two forces acting on the rigid rod causes clockwise moment?
2) Is the rod in equilibrium?
3) The direction of 20 kgf force is reversed. What is the magnitude of the resultant moment of the forces on the rod?
Advertisements
Solution
1) The force of 12 gf causes a clockwise moment.
2) Clockwise moment = 12 x 10 gf cm
= 120 gf cm
Anti clockwise moment = 20 x 6 gf cm
= 120 gf cm
∵ Clockwise moment = Anti clockwise moment
∴ The rod is in equilibrium.
3) If the direction of 20 gf force is reversed, it will also create a clockwise moment.
Resultant moment = (120 + 120) gf cm (clockwise)
= 240 gf cm
APPEARS IN
RELATED QUESTIONS
The moment of a force of 25 N about a point is 2.5 N m. Find the perpendicular distance of force from that point.
A wheel of diameter 2 m can be rotated about an axis passing through its center by a moment of force equal to 2.0 Nm. What minimum force must be applied on its rim?
State Newton's Second law of motion. Under what conditon does it take the form F = ma?
A wheel of diameter 2 m is shown in the figure with the axle at O. A force F = 2 N is applied at B in the direction shown in the figure. Calculate the moment of force about
- the centre O, and
- the point A.
Classify the following amongst contact and non-contact forces.
Frictional force
The diagram shows a uniform metre rule weighing 100gf, pivoted at its centre O. Two weights 150gf and 250gf hang from the point A and B respectively of the metre rule such that OA = 40 cm and OB = 20 cm. Calculate :
the total clockwise moment about O
How does the distance of separation between two bodies affect the magnitude of the non-contact force between them?
State two factors on which moment of the force about a point depends.
Calculate the minimum distance between point of application of force and axis of rotation of a rigid body, if a force 125 N produces a moment of force of 25.75 Nm.
