Advertisements
Advertisements
प्रश्न
A uniform metre scale is balanced at a 40 cm mark when weights of 20 gf and 5 gf are suspended at 5 cm mark and 75 cm mark respectively. Calculate the weight of metre scale.
Advertisements
उत्तर
A metre scale is a uniform, therefore its weight acts at a 50 cm mark.
Taking moments about to cm mark.

A moment in the clockwise direction,
= W × 10 cm + 5 gf × 35 cm
= 10 W cm + 175 gf cm.
moment in anti-clockwise direction,
= 20 gf × 35 cm
= 700 gf cm.
By the law of moments,
Moments in clockwise direction = moments in anti-clockwise directions.
10 W cm + 175 gf cm = 700 gf cm
∴ 10 W cm = (700 − 175) gf cm
∴ W = `525/10` gf = 52.5 gf.
संबंधित प्रश्न
Where can a body execute free vibrations?
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?
Define force.
What do you understand by the clockwise and anticlockwise moment of force? When is it taken positive?
The stone of hand flour grinder is provided with a handle near its rim. Give reason.
A steering wheel of diameter 0.5 m is rotated anticlockwise by applying two forces each of magnitude 6 N. Draw a diagram to show the application of forces and calculate the moment of forces applied.
Classify the following amongst contact and non-contact forces.
normal reaction force,
A wheel of diameter 3 m is shown in fig. 2 with axle at 0. A force F = 8 N is applied at Q in the direction shown in figure. Calculate the moment of force about:
(i) centre o, and
(ii) point p.

A jack screw is provided with a long arm. Explain why?
State the units of moment of force.
